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© Frank Woutersen 2008 - 2019 Batch Control Part 1: Models Terminology Approved 23 October 1995 ANSI/ISA–88.01–1995 Formerly ANSI/ISA–S88.01–1995 AMERICAN NATIONAL STANDARD ISA Instrumentation, Systems, Automation Society – TM Copyright  1995 Instrument Society America. rights reserved. Printed United States America. part publication may reproduced, stored retrieval system, or transmitted form means (electronic, mechanical, photocopying, recording, or otherwise), without prior written permission publisher. ISA 67 Alexander Drive P.O. Box 12277 Research Triangle Park, North Carolina 27709 ANSI/ISA-88.01-1995, Batch Control, Part 1: Models Terminology ISBN: 1-55617-562-0 ANSI/ISA-S88.01-1995 3 Preface This preface well footnotes annexes included informational purposes are part ANSI/ISA-88.01-1995. This standard has been prepared part service ISA, international society for measurement control, toward goal uniformity field instrumentation. real value, document should static should subject periodic review. Toward this end, Society welcomes comments criticisms asks they addressed Secretary, Standards Practices Board; ISA; 67 Alexander Drive; P. O. Box 12277; Research Triangle Park, NC 27709; Telephone (919) 990-9227; Fax (919) 549-8288;e-mail: standards@isa.org. ISA Standards Practices Department aware growing need attention metric system units general, International System Units (SI) particular, preparation instrumentation standards, recommended practices, technical reports. Department further aware benefits USA users ISA standards incorporating suitable references SI (and metric system) business professional dealings with other countries. Toward end, Department endeavor introduce SI-acceptable metric units new revised standards greatest extent possible. Metric Practice Guide, which has been published Institute Electrical Electronics Engineers ANSI/IEEE Std. 268-1992, future revisions, reference guide definitions, symbols, abbreviations, conversion factors. It policy ISA encourage welcome participation concerned individuals interests development ISA standards, recommended practices, technical reports. Participation ISA standards-making process individual way constitutes endorsement employer individual, ISA, standards, recommended practices, technical reports ISA develops. This standard structured follow IEC guidelines. Therefore, first three sections discuss Scope standard, Normative References, Definitions, order. Section 4 entitled Batch Processes Equipment. intent section discuss batch processing batch manufacturing plant. Things involved batch manufacturing (e.g., batch process classification, equipment, processes) described this section. models terminology defined section provide foundation for understanding application batch control batch manufacturing plant Sections 5 6. Section 5 entitled Batch Control Concepts. intent section discuss key aspects of batch processing batch manufacturing plants. control finally introduced to physical equipment, concept equipment entities introduced. Recipes introduced Section 5. concepts Allocation Arbitration, Modes States, Exception Handling introduced section so they can applied discussions Section 6. Section 6 entitled Batch Control Activities Functions. intent models terminology introduced section establish necessary control activities are needed address diverse control requirements batch manufacturing. concept Control Activity Model introduced section. Each control activity from Control Activity Model discussed terms individual control functions needed address batch processing, manufacturing, control requirements previous two sections. Note 4 ANSI/ISA-S88.01-1995 that there attempt define compliance requirements within section since overall purpose standard define common approach defining modeling batch processes associated controls. This standard (Part 1, Models Terminology) intended people who are — involved designing and/or operating batch manufacturing plants; — responsible specifying controls associated application programs batch manufacturing plants; or — involved design marketing products area batch control. following people served active members ISA Committee SP88: NAME COMPANY L. Craig, Chairman Rohm Haas Company * R. Mergen, Past Chairman Lubrizol Corporation *T. Fisher, Past Chairman/Editor Lubrizol Corporation C. Gross, Past Managing Director Dow Chemical Company *M. Albano Honeywell, Inc. A. Aujesky ICI Australia Engineering *J. Barrault Siemens G. Barron John Brown Engineers & Constructors BV R. Baxter Eastman Kodak Company *D. Brandl Groupe Schneider B. Braunstein Exxon Chemical Company *E. Bristol Foxboro Company M. Bruns Hoechst AG R. Bullotta WonderWare *H. Burns Fisher • Rosemount G. Carlo-Stella Batch Systems International *B. Casey Groupe Schneider D. Chappell Procter & Gamble Company *L. Charpentier GSE Process Solutions *T. Crowl Moore Products Company *B. Cubizolles Siemens M. Dawson Smith-Kline Beecham *K. Dittman Johnson Yokogawa *D. Dodd Foxboro Company *S. Duff Moore Products Company *C. Eaves Intellution, Inc. *D. Edwards Johnson Yokogawa *D. Emerson GSE Process Solutions *S. Farmer ABB Process Automation, Inc. G. Felton Ashland Chemical H. Fittler Honeywell Regelsysteme *A. Ghosh Foxboro Company *P. Gustafson Hartmann & Braun * vote per company ANSI/ISA-S88.01-1995 5 NAME COMPANY * R. Hall PID, Inc. *W. Hawkins Fisher • Rosemount N. Haxthausen Novo-Nordisk Engineering *C. Hertz Bailey Controls Company S. Hjelmager CRI Industrial Systems A/S T. Hoekstra Yokogawa Europe *T. Hollowell Fisher • Rosemount *D. Hornbeck Allen-Bradley Co. *D. Imming Fisher • Rosemount *S. Jayanthi Intellution, Inc. *B. Jensen Johnson Yokogawa T. Jonsson ABB Automation AB H. Kayser Consultant G. Klipfel Upjohn Company *D. Leach Air Products & Chemicals Company T. Leffert 3M *B. Lightle Allen-Bradley Company *W. Loner Bailey Controls Company R. Lotz Consultant B. Lozier Pacific Access Computer *D. Macias Fisher • Rosemount S. Mallaband Bass Brewers, Ltd. *E. Massey Honeywell, Inc. W. McFarlane Valmet Automation, Inc. *N. Meierhoefer Hartmann & Braun *T. Müller-Heinzerling Siemens L. Natiello Kraft General Foods K. Ng Office Naval Research *P. Nowicki ABB Process Automation, Inc. A. Pampel A. F. Pampel Consulting *A. Pawlus Honeywell, Inc. *S. Prichard Fisher • Rosemount A. Rabinowitz Consultant H. Rosenof Gensym Corporation *J. Ruhe Bailey Controls Company P. Saebye CRI Industrial Systems A/S *M. Saucier PID, Inc. *C. Schmidt Siemens *J. Schwatmann Siemens J. Shaffer Consultant R. Shilts Modicon AEG E. Smith Good Manufacturing Practices, Inc. *K. Spencer ABB Process Automation, Inc. *J. Sten E. I. du Pont de Nemours & Company (Ret.) *F. Sutter Fisher • Rosemount *B. Sykes Johnson Yokogawa R. Thome Merck T. Tom Elsag Bailey * vote per company 6 ANSI/ISA-S88.01-1995 NAME COMPANY J. Unger Chesebrough-Pond's (Unilever) * J. Vardy Foxboro Company J. Verhulst Biogen, Inc. J. Via III Alcon Labs *N. Vroom Honeywell, Inc. *H. Wähner Hartmann & Braun *M. Warburton ABB Process Automation, Inc. R. Watson Mettler-Toledo, Inc. *A. Webster E. I. du Pont de Nemours & Company A. Weidenbach Eastman Chemical Company *S. Whitman Johnson Yokogawa *E. Whitmer Honeywell, Inc. *G. Wilcox Air Products & Chemicals Company This published standard was approved publication ISA Standards Practices Board February 1995. NAME COMPANY M. Widmeyer, Vice President Supply System H. Baumann H. D. Baumann & Associates, Ltd. D. Bishop Chevron USA Production Company P. Brett Honeywell, Inc. W. Calder III Foxboro Company H. Dammeyer Ohio State University R. Dieck Pratt & Whitney H. Hopkins Utility Products Arizona A. Iverson Lyondell Petrochemical Company K. Lindner Endress + Hauser GmbH + Company T. McAvinew Metro Wastewater Reclamation District A. McCauley, Jr. Chagrin Valley Controls, Inc. G. McFarland Consultant J. Mock Consultant E. Montgomery Fluor Daniel, Inc. D. Rapley Rapley Engineering Services R. Reimer Allen-Bradley Company R. Webb Pacific Gas & Electric Company W. Weidman Consultant J. Weiss Electric Power Research Institute J. Whetstone National Institute Standards & Technology C. Williams Eastman Kodak Company G. Wood Graeme Wood Consulting M. Zielinski Fisher • Rosemount * vote per company ANSI/ISA-S88.01-1995 7 Contents 1 Scope .................................................................................................................................... 13 2 Normative references .......................................................................................................... 13 3 Definitions ............................................................................................................................ 13 4 Batch processes equipment ........................................................................................ 17 4.1 Processes, batches, batch processes ................................................................. 18 4.2 Physical model ........................................................................................................... 20 4.3 Process cell classification ........................................................................................... 23 5 Batch control concepts ....................................................................................................... 27 5.1 Structure batch control .......................................................................................... 27 5.2 Equipment entities ...................................................................................................... 30 5.3 Recipes ....................................................................................................................... 35 5.4 Production plans schedules ................................................................................. 51 5.5 Production information ................................................................................................ 52 5.6 Allocation arbitration ............................................................................................ 54 5.7 Modes states ....................................................................................................... 55 5.8 Exception handling ..................................................................................................... 61 6 Batch control activities functions ............................................................................... 61 6.1 Control activities ......................................................................................................... 62 6.2 Recipe management .................................................................................................. 66 6.3 Production planning scheduling ........................................................................... 70 6.4 Production information management .......................................................................... 70 6.5 Process management ................................................................................................. 76 6.6 Unit supervision .......................................................................................................... 80 6.7 Process control ........................................................................................................... 82 6.8 Personnel environmental protection .................................................................... 84 Annexes — (normative) Model philosophy ........................................................................................... 87 B — (informative) Bibliography ................................................................................................. 95 8 ANSI/ISA-S88.01-1995 Figures 1 — Process model (Entity - Relationship diagram) ............................................................... 19 2 — Physical model ................................................................................................................ 21 3 — Single-path structure ....................................................................................................... 24 4 — Multiple-path structure..................................................................................................... 25 5 — Network structure ............................................................................................................ 26 6 — Procedural control model ................................................................................................ 28 7 — Procedural control/equipment mapping achieve process functionality........................ 31 8 — Recipe types.................................................................................................................... 36 9 — General recipe procedure................................................................................................ 40 10 — Master recipe procedure ................................................................................................. 41 11 — Procedural element relationships site recipe master recipe........................... 42 12 — Control recipe procedure/equipment control separation ................................................. 44 13 — Control recipe procedure example with unit procedures, operations, phases.......... 46 14 — Control recipe procedure example with unit procedures operations ........................ 47 15 — Control recipe procedure example with unit procedures................................................. 48 16 — Control recipe procedure example with only procedure............................................... 49 17 — Control recipe procedure/equipment control collapsibility examples............................... 50 18 — State transition diagram example states procedural elements ............................. 59 19 — Control activity model...................................................................................................... 63 20 — Simultaneous definition/selection procedural elements equipment entities ......... 66 21 — Recipe management ....................................................................................................... 67 22 — Process management ..................................................................................................... 76 23 — Unit supervision............................................................................................................... 80 24 — Process control................................................................................................................ 83 A.1 — Basic looped associations Entity-Relationship diagrams..................................... 88 A.2 — Labeled associations Entity-Relationship diagrams.................................................... 89 A.3 — Process model (Entity-Relationship diagram)................................................................. 90 A.4 — Process control (control activity with breakdown into control functions)......................... 91 A.5 — State transition diagram.................................................................................................. 92 A.6 — Single-path structure (physical drawing)......................................................................... 92 A.7 — Site recipe procedure master recipe procedure relationship (nesting model)............. 93 Tables 1 — Possible implementations example modes ..................................................................... 57 2 — State transition matrix example states procedural elements .................................... 58 ANSI/ISA-S88.01-1995 9 Foreword 1) formal decisions agreements IEC technical matters, prepared technical committees which National Committees having special interest therein are represented, express, nearly possible, international consensus opinion subjects dealt with. 2) They have form recommendations international use they accepted National Committees sense. 3) order promote international unification, IEC expresses wish National Committees should adopt text IEC recommendation national rules insofar national conditions permit. divergence between IEC recommendation corresponding national rules should, far possible, clearly indicated latter. 4) IEC has laid down procedure concerning marking indication approval has responsibility when item equipment declared comply with its recommendations. This part International Standard has been prepared IEC/SC65A/WG11 ISA SP88. It forms part 1 series, other part being Part 2: Data structures guidelines for languages. Annex forms integral part part international standard. Refer Annex explanation format general associations used creating diagrams this international standard. Annex B information only. ANSI/ISA-S88.01-1995 11 Introduction This part international standard Batch Control provides standard models terminology defining control requirements batch manufacturing plants. models terminology defined standard — emphasize good practices design operation batch manufacturing plants; — can used improve control batch manufacturing plants; — can applied regardless degree automation. Specifically, standard provides standard terminology consistent set concepts models batch manufacturing plants batch control improve communications between parties involved; will — reduce user's time reach full production levels new products; — enable vendors supply appropriate tools implementing batch control; — enable users better identify needs; — make recipe development straightforward enough accomplished without services control systems engineer; — reduce cost automating batch processes; — reduce life-cycle engineering efforts. It intent standard to — suggest there only way implement apply batch control; — force users abandon current way dealing with batch processes; or — restrict development area batch control. models presented standard presumed complete indicated. However, they may collapsed expanded described below. unit control module levels may omitted from physical model. master recipe control recipe may be omitted from recipe types model. Specific rules collapsing expanding these models are covered standard. — Collapsing: Elements models may omitted long model remains consistent, functions element removed taken into account. — Expanding: Elements may added modules. When they added between related elements, integrity original relationship should maintained. ANSI/ISA-S88.01-1995 13 1 Scope This part standard Batch Control defines reference models batch control used process industries terminology helps explain relationships between these models terms. standard may apply batch control applications. 2 Normative references following normative documents contain provisions, which through reference text, constitute provisions part standard. time publication, editions indicated valid. normative documents subject revision, parties agreements based this part standard encouraged investigate possibility applying most recent editions normative documents indicated below. Members IEC ISO maintain registers currently valid normative documents. IEC 848: 1988, Preparation function charts control systems NOTE – Structures defined IEC 848 may useful definition procedural control, particular definition phase. IEC 902: 1987, Industrial-process measurement control — Terms definitions NOTE – Definitions found IEC 902 used basis definitions standard. necessary, specific connotation terms used batch control included definitions standard. 3 Definitions For purposes part international standard, following definitions apply. 3.1 allocation: form coordination control assigns resource batch unit. NOTE – allocation can entire resource portions resource. 3.2 arbitration: form coordination control determines how resource should allocated when there more requests resource than can accommodated time. 3.3 area: component batch manufacturing site identified physical, geographical, or logical segmentation within site. NOTE – area may contain process cells, units, equipment modules, control modules. 3.4 basic control: Control dedicated establishing maintaining specific state of equipment process condition. NOTE – Basic control may include regulatory control, interlocking, monitoring, exception handling, discrete sequential control. 14 ANSI/ISA-S88.01-1995 3.5 batch: 1.) material being produced has been produced single execution of batch process. 2.) entity represents production material point process. NOTE – Batch means both material made during process also entity represents production material. Batch used abstract contraction words "the production of batch." 3.6 batch control: Control activities control functions provide means process finite quantities input materials subjecting them ordered set processing activities over finite period time using more pieces equipment. 3.7 batch process: process leads production finite quantities material by subjecting quantities input materials ordered set processing activities over finite period of time using more pieces equipment. 3.8 batch schedule: list batches produced specific process cell. NOTE – batch schedule typically contains such information what produced, how much to produced, when what order batches produced, what equipment used. 3.9 common resource: resource can provide services more than requester. NOTE – Common resources identified either exclusive-use resources shared-use resources (3.22 3.54). 3.10 control module: lowest level grouping equipment physical model can carry out basic control. NOTE – term applies both physical equipment equipment entity. 3.11 control recipe: type recipe which, through its execution, defines manufacture single batch specific product. 3.12 coordination control: type control directs, initiates, and/or modifies execution of procedural control utilization equipment entities. 3.13 enterprise: organization coordinates operation more sites. 3.14 equipment control: equipment-specific functionality provides actual control capability equipment entity, including procedural, basic, coordination control, that part recipe. 3.15 equipment entity: collection physical processing control equipment equipment control grouped together perform certain control function set control functions. 3.16 equipment module: functional group equipment can carry out finite number of specific minor processing activities. NOTES 1 equipment module typically centered around piece process equipment (a weigh tank, process heater, scrubber, etc.). term applies both physical equipment equipment entity. 2 Examples minor process activities dosing weighing. 3.17 equipment operation: operation part equipment control. 3.18 equipment phase: phase part equipment control. ANSI/ISA-S88.01-1995 15 3.19 equipment procedure: procedure part equipment control. 3.20 equipment unit procedure: unit procedure part equipment control. 3.21 exception handling: Those functions deal with plant process contingencies other events which occur outside normal desired behavior batch control. 3.22 exclusive-use resource: common resource only user can use given time. 3.23 formula: category recipe information includes process inputs, process parameters, process outputs. 3.24 general recipe: type recipe expresses equipment site independent processing requirements. 3.25 header: Information about purpose, source version recipe such recipe product identification, creator, issue date. 3.26 ID: unique identifier batches, lots, operators, technicians, raw materials. 3.27 line; train: See definition train. 3.28 lot: unique amount material having set common traits. NOTE – Some examples common traits material source, master recipe used produce material, distinct physical properties. 3.29 master recipe: type recipe accounts equipment capabilities may include process cell-specific information. 3.30 mode: manner which transition sequential functions carried out within procedural element accessibility manipulating states equipment entities manually or other types control. 3.31 operation: procedural element defining independent processing activity consisting of algorithm necessary initiation, organization, control phases. 3.32 path; stream: order equipment within process cell used, expected to be used, production specific batch. 3.33 personnel environmental protection: control activity that — prevents events from occurring would cause process react manner that would jeopardize personnel safety and/or harm environment; and/or — takes additional measures, such starting standby equipment, prevent abnormal condition from proceeding more undesirable state would jeopardize personnel safety and/or harm environment. 3.34 phase: lowest level procedural element procedural control model. 3.35 procedural control: Control directs equipment-oriented actions take place ordered sequence order carry out some process-oriented task. 3.36 procedural element: building block procedural control defined procedural control model. 16 ANSI/ISA-S88.01-1995 3.37 procedure: strategy carrying out process. NOTE – general, it refers strategy making batch within process cell. It may also refer to process does result production product, such clean-in-place procedure. 3.38 process: sequence chemical, physical, biological activities conversion, transport, storage material energy. 3.39 process action: Minor processing activities combined make up process operation. NOTE – Process actions lowest level processing activity within process model. 3.40 process cell: logical grouping equipment includes equipment required for production more batches. It defines span logical control set process equipment within area. NOTE – term applies both physical equipment equipment entity. 3.41 process control: control activity includes control functions needed provide sequential, regulatory, discrete control gather display data. 3.42 process input: identification quantity raw material other resource required to make product. 3.43 process management: control activity includes control functions needed to manage batch production within process cell. 3.44 process operation: major processing activity usually results chemical physical change material being processed defined without consideration actual target equipment configuration. 3.45 process output: identification quantity material energy expected result from execution control recipe. 3.46 process parameter: Information needed manufacture material does fall into classification process input process output. NOTE – Examples process parameter information temperature, pressure, time. 3.47 process stage: part process usually operates independently from other process stages usually results planned sequence chemical physical changes material being processed. 3.48 recipe: necessary set information uniquely defines production requirements for specific product. NOTE – There types recipes defined standard: general, site, master, control. 3.49 recipe management: control activity includes control functions needed to create, store, maintain general, site, master recipes. 3.50 recipe operation: operation part recipe procedure master control recipe. 3.51 recipe phase: phase part recipe procedure master control recipe. 3.52 recipe procedure: part recipe defines strategy producing batch. ANSI/ISA-S88.01-1995 17 3.53 recipe unit procedure: unit procedure part recipe procedure master or control recipe. 3.54 shared-use resource: common resource can used more than user time. 3.55 site: component batch manufacturing enterprise identified physical, geographical, or logical segmentation within enterprise. NOTE – site may contain areas, process cells, units, equipment modules, control modules. 3.56 site recipe: type recipe site specific. NOTE – Site recipes may derived from general recipes recognizing local constraints, such language available raw materials. 3.57 state: condition equipment entity procedural element given time. NOTE – number possible states names vary equipment procedural elements. 3.58 stream; path: See definition path. 3.59 train; line: collection more units associated lower level equipment groupings that has ability used make batch material. 3.60 unit: collection associated control modules and/or equipment modules other process equipment which more major processing activities can conducted. NOTES 1 Units presumed operate only batch time. Units operate relatively independently of another. 2 term applies both physical equipment equipment entity. 3 Examples major processing activities react, crystallize, make solution. 3.61 unit procedure: strategy carrying out contiguous process within unit. It consists of contiguous operations algorithm necessary initiation, organization, control of those operations. 3.62 unit recipe: part control recipe uniquely defines contiguous production requirements unit. NOTE – unit recipe contains unit procedure its related formula, header, equipment requirements, other information. 3.63 unit supervision: control activity includes control functions needed supervise unit unit's resources. 4 Batch processes equipment This section provides overview batch processing batch manufacturing plant. models terminology defined section provide foundation understanding application batch control batch manufacturing plant Sections 5 6. Specifically, this section discusses batch processes, physical model, process cell classification. 18 ANSI/ISA-S88.01-1995 4.1 Processes, batches, batch processes process sequence chemical, physical biological activities conversion, transport or storage material energy. Industrial manufacturing processes can generally classified continuous, discrete parts manufacturing, batch. How process classified depends whether output from process appears continuous flow (continuous), finite quantities of parts (discrete parts manufacturing), finite quantities material (batches). Although aspects standard may apply discrete parts manufacturing continuous processes, this standard does specifically address these types processes. 4.1.1 Continuous processes continuous process, materials passed continuous flow through processing equipment. Once established steady operating state, nature process dependent length time operation. Start-ups, transitions, shutdowns do usually contribute achieving desired processing. 4.1.2 Discrete parts manufacturing processes discrete parts manufacturing process, products classified into production lots are based common raw materials, production requirements, production histories. discrete parts manufacturing process, specified quantity product moves unit (group of parts) between workstations, each part maintains its unique identity. 4.1.3 Batch processes batch processes addressed standard lead production finite quantities of material (batches) subjecting quantities input materials defined order processing actions using more pieces equipment. product produced batch process called batch. Batch processes discontinuous processes. Batch processes neither discrete nor continuous; however, they have characteristics both. subdivisions batch process can organized hierarchical fashion shown Figure 1. example batch process used section production polyvinyl chloride by polymerization vinyl chloride monomer. ANSI/ISA-S88.01-1995 19 Figure 1 — Process model (Entity - Relationship diagram) Process Process Stage Process Operation Process Action consists ordered set of consists ordered set of consists ordered set of 20 ANSI/ISA-S88.01-1995 Process stages process consists more process stages which organized ordered set, which can serial, parallel, both. process stage part process usually operates independently from other process stages. It usually results planned sequence of chemical physical changes material being processed. Typical process stages polyvinyl chloride process might following: — Polymerize: Polymerize vinyl chloride monomer into polyvinyl chloride. — Recover: Recover residual vinyl chloride monomer. — Dry: Dry polyvinyl chloride. Process operations Each process stage consists ordered set more process operations. Process operations represent major processing activities. process operation usually results chemical physical change material being processed. Typical process operations polymerization vinyl chloride monomer into polyvinyl chloride process stage might following: — Prepare reactor: Evacuate reactor remove oxygen. — Charge: Add demineralized water surfactants. — React: Add vinyl chloride monomer catalyst, heat 55 - 60°C, hold this temperature until reactor pressure decreases. Process actions Each process operation can subdivided into ordered set more process actions that carry out processing required process operation. Process actions describe minor processing activities combined make up process operation. Typical process actions for react process operation might following: — Add: Add required amount catalyst reactor. — Add: Add required amount vinyl chloride monomer reactor. — Heat: Heat reactor contents 55 - 60°C. — Hold: Hold reactor contents 55 - 60°C until reactor pressure decreases. 4.2 Physical model This section discusses physical model can used describe physical assets enterprise terms enterprises, sites, areas, process cells, units, equipment modules, control modules. physical assets enterprise involved batch manufacturing usually organized hierarchical fashion described Figure 2. Lower level groupings combined form higher levels hierarchy. some cases, grouping within level may incorporated into another grouping same level. model has seven levels, starting top with enterprise, site, area. These three levels frequently defined business considerations modeled further ANSI/ISA-S88.01-1995 21 document. three higher levels part model properly identify relationship of lower level equipment manufacturing enterprise. lower levels model refer specific equipment types. equipment type Figure 2 collection physical processing control equipment grouped together specific purpose. lower levels model specific technically defined bounded groupings equipment. lower equipment levels (process cells, units, equipment modules, control modules) defined engineering activities (see 5.2.3 6.1.3). During these engineering activities, equipment lower levels grouped together form new higher level equipment grouping. done simplify operation equipment by treating it single larger piece equipment. Once created, equipment cannot split up except re-engineering equipment level. NOTE – boxes top three levels shown with slashed lines indicate criteria that are used configuring boundaries these three levels often beyond scope batch control standard. Therefore, criteria configuring boundaries these three levels physical model discussed standard. Figure 2 — Physical model Equipment Module Control Module may contain may contain may contain may contain must contain may contain may contain may contain Site Enterprise Area Process Cell Unit 22 ANSI/ISA-S88.01-1995 4.2.1 Enterprise level enterprise collection more sites. It may contain sites, areas, process cells, units, equipment modules, control modules. enterprise responsible determining what products manufactured, which sites they manufactured, general how they manufactured. There many factors other than batch control affect boundaries enterprise. Therefore, criteria configuring boundaries enterprise covered this standard. 4.2.2 Site level site physical, geographical, logical grouping determined enterprise. It may contain areas, process cells, units, equipment modules, control modules. boundaries site usually based organizational business criteria opposed to technical criteria. There many factors other than batch control affect these boundaries. Therefore, criteria configuring boundaries site covered standard. 4.2.3 Area level area physical, geographical, logical grouping determined site. It may contain process cells, units, equipment modules, control modules. boundaries area usually based organizational business criteria opposed to technical criteria. There many factors other than batch control affect these boundaries. Therefore, criteria configuring boundaries area covered standard. 4.2.4 Process cell level process cell contains units, equipment modules, control modules required to make more batches. Process control activities must respond combination control requirements using variety of methods techniques. Requirements cause physical control actions may include responses process conditions comply with administrative requirements. frequently recognized subdivision process cell train. train composed units other equipment may utilized specific batch. batch does always use equipment train. Furthermore, more than batch more than product may use train simultaneously. order equipment actually used expected used batch called path. Although process cell may contain more than train, train may contain equipment outside boundaries process cell. process cell logical grouping equipment includes equipment required for production more batches. It defines span logical control set process equipment within area. existence process cell allows production scheduling process cell basis, also allows process cell-wide control strategies designed. These process cell-wide control strategies might particularly useful emergency situations. 4.2.5 Unit level unit made up equipment modules control modules. modules make up unit may configured part unit may acquired temporarily carry out specific tasks. more major processing activities — such react, crystallize, make solution — can be conducted unit. It combines necessary physical processing control equipment ANSI/ISA-S88.01-1995 23 required perform those activities independent equipment grouping. It usually centered major piece processing equipment, such mixing tank reactor. Physically, it includes can acquire services logically related equipment necessary complete major processing task(s) required it. Units operate relatively independently each other. unit frequently contains operates complete batch material some point processing sequence batch. However, other circumstances it may contain operate only portion batch. standard presumes unit does operate more than batch same time. 4.2.6 Equipment module level Physically, equipment module may made up control modules subordinate equipment modules. equipment module may part unit stand-alone equipment grouping within process cell. If engineered stand-alone equipment grouping, it can exclusive-use resource shared-use resource. equipment module can carry out finite number specific minor processing activities such dosing weighing. It combines necessary physical processing control equipment required perform those activities. It usually centered piece processing equipment, such filter. Functionally, scope equipment module defined finite tasks it designed carry out. 4.2.7 Control module level control module typically collection sensors, actuators, other control modules, associated processing equipment that, from point view control, operated single entity. control module can also made up other control modules. example, header control module could defined combination several on/off automatic block valve control modules. Some examples control modules are — regulating device consisting transmitter, controller, control valve operated via set point device; — state-oriented device consists on/off automatic block valve with position feedback switches, operated via set point device; or — header contains several on/off automatic block valves coordinates valves direct flow several destinations based upon set point directed header control module. 4.3 Process cell classification This section discusses classification process cells number different products manufactured process cell physical structure equipment used manufacturing. 4.3.1 Classification number products process cell classified single-product multi-product based number products planned production process cell. single product process cell produces same product each batch. Variations procedures parameters possible. example, variations may occur order compensate 24 ANSI/ISA-S88.01-1995 differences equipment, compensate substitute raw materials, compensate changes environmental conditions, optimize process. multi-product process cell produces different products utilizing different methods production or control. There two possibilities: — products produced with same procedure using different formula values (varying materials and/or process parameters). — products produced using different procedures. 4.3.2 Classification physical structure basic types physical structures discussed here single path, multiple path, network. single-path structure group units through which batch passes sequentially (see Figure 3). single-path structure could single unit, such reactor, several units sequence. Multiple input materials typically used; multiple finished materials may be generated. Several batches may progress same time. Figure 3 — Single-path structure UNIT 1 UNIT 2 Input Materials Storage Finished Materials Storage ANSI/ISA-S88.01-1995 25 multiple-path structure shown Figure 4. It consists multiple single-path structures parallel with product transfer between them. units may share raw material sources product storage. Several batches may progress same time. Although units within multi-path structure may physically similar, it possible have paths units within multipath structure radically different physical design. Figure 4 — Multiple-path structure Unit 1 Unit 2 Unit 4 Input Materials Storage Finished Materials Storage Unit 3 Unit 5 Unit 6 26 ANSI/ISA-S88.01-1995 network structure shown Figure 5. paths may either fixed variable. When paths fixed, same units used same sequence. When path variable, sequence may determined beginning batch it may determined batch being produced. path could also totally flexible. example, batch would have to start either Unit 1 Unit 3; it could start with unit take multiple paths through process cell. units themselves may portable within process cell. case, verification process connections may important part procedures. Note that several batches may production same time. units may share raw material sources product storage. Figure 5 — Network structure Unit 1 Unit 2 Unit 3 Input Materials Storage Finished Materials Storage Unit 4 ANSI/ISA-S88.01-1995 27 5 Batch control concepts This section discusses batch control concepts needed address batch processing/batch manufacturing needs presented preceding section define consistent way of operating batch manufacturing plant. structure batch control discussed introduces three types control needed batch manufacturing. When these control types applied to equipment, resulting equipment entities provide process functionality control capability. concept recipes discussed, including types recipes described standard contents these recipes (in terms information categories used describe recipe). relationship established between procedure recipe control associated with specific equipment entities (equipment control). concept collapsibility of recipe procedure equipment control discussed. Recipe transportability criteria are introduced types recipes. Production plans schedules, reference information, production information, allocation arbitration, modes states, exception handling other batch control concepts discussed section. intent models terminology introduced section establish necessary batch control understanding so control functions needed address diverse control requirements batch manufacturing can discussed Section 6. 5.1 Structure batch control Section 4 introduced physical model defined terms hierarchy equipment typically found batch manufacturing environment. section describes three types control (basic control, procedural control, coordination control) typically needed batch manufacturing. 5.1.1 Basic control Basic control comprises control dedicated establishing maintaining specific state of equipment process. Basic control — includes regulatory control, interlocking, monitoring, exception handling, repetitive discrete sequential control; — may respond process conditions could influence control outputs trigger corrective actions; — may activated, deactivated, modified operator commands procedural or coordination control. Basic control batch environment principle different from control continuous processes. However, batch environment, there may higher requirements ability for basic control receive commands modify its behavior based these commands. 5.1.2 Procedural control Procedural control directs equipment-oriented actions take place ordered sequence order carry out process-oriented task. 28 ANSI/ISA-S88.01-1995 Procedural control characteristic batch processes. It control enables equipment to perform batch process. Procedural control made up procedural elements combined hierarchical manner to accomplish task complete process defined process model. hierarchy of identified named procedural elements illustrated Figure 6 consists procedures, unit procedures, operations, phases. Figure 6 — Procedural control model Procedure Unit Procedure Operation Phase consists ordered set of consists ordered set of consists ordered set of ANSI/ISA-S88.01-1995 29 Procedure procedure highest level hierarchy defines strategy carrying out major processing action such making batch. It defined terms ordered set unit procedures. example procedure "Make PVC." Unit procedure unit procedure consists ordered set operations causes contiguous production sequence take place within unit. Only operation presumed active unit any time. operation carried completion single unit. However, multiple unit procedures of procedure may run concurrently, each different units. Examples unit procedures include following: — Polymerize VCM. — Recover residual VCM. — Dry PVC. Operation operation ordered set phases defines major processing sequence takes material being processed from state another, usually involving chemical physical change. It often desirable locate operation boundaries points procedure where normal processing can safely suspended. Examples operations include following: — Preparation: Pull vacuum reactor coat walls with antifoulant. — Charge: Add demineralized water surfactants. — React: Add VCM catalyst, heat, wait reactor pressure drop. Phase smallest element procedural control can accomplish process-oriented task phase. phase may subdivided into smaller parts. steps transitions described IEC 848: 1988 document method defining subdivisions phase. phase can issue more commands cause more actions, such — Enabling disabling regulating state-oriented types basic control specifying set points initial output values — Setting, clearing, changing alarm other limits — Setting changing controller constants, controller modes, types algorithms — Reading process variables, such gas density, gas temperature, volumetric flow rate from flowmeter, calculating mass flow rate through flowmeter — Conducting operator authorization checks. execution phase may result — commands basic control; — commands other phases (either same another equipment entity); and/or — collection data. 30 ANSI/ISA-S88.01-1995 intent phase cause define process-oriented action, while logic set of steps make up phase equipment specific. Examples phases include following: — Add VCM. — Add catalyst. — Heat. 5.1.3 Coordination control Coordination control directs, initiates, and/or modifies execution procedural control utilization equipment entities. It time varying nature, like procedural control, it structured along specific process-oriented task. Examples coordination control algorithms for — supervising availability capacity equipment; — allocating equipment batches; — arbitrating requests allocation; — coordinating common resource equipment; — selecting procedural elements executed; — propagating modes. control functions needed implement coordination control discussed more detail Section 6 under topic control activities. 5.2 Equipment entities This section discusses equipment entities formed from combination equipment control physical equipment. combination results equipment entities: process cells, units, equipment modules, control modules. Guidelines structuring these equipment entities also discussed. When terms process cell, unit, equipment module, control module used, they generally refer equipment its associated equipment control. Whether equipment control equipment entity implemented manually way automation, it only through exercise equipment control equipment can produce batch. notion equipment control being part equipment entity understood logically. It statement physical implementation equipment control. However, it must be possible identify equipment control particular equipment entity. This interaction equipment control physical equipment described purposely without any reference language implementation. intent describe framework within which equipment control physical equipment may defined discussed. 5.2.1 Procedural control model/physical model/process model relationship general relationship between procedural control model, physical model, process model illustrated Figure 7. mapping procedural control with individual equipment provides processing functionality described process model. ANSI/ISA-S88.01-1995 31 concept equipment capabilities usage these capabilities accomplish processing tasks major point standard. procedural control capability equipment entities mechanism enables this. procedural control may entirely defined part of equipment control, it may based procedural information passed equipment entity from recipe. Figure 7 — Procedural control/equipment mapping achieve process functionality Procedural Control Model Procedural Elements combined with combined with combined with combined with combined with provides process funtionality to carry out provides process funtionality to carry out provides process funtionality to carry out provides process funtionality to carry out provides process funtionality to carry out Procedure (s) Unit Procedure (s) Operation (s) Phase (s) Phase (s) (See Figure 6) (See Figure 2) (See Figure 1) Process Cell (s) Unit (s) Unit (s) Unit (s) Equipment Module (s) Process Process Stage Process Operation Process Action Process Action Equipment Resulting Process Functionality Physical Model (Lower Portion) Process Model 32 ANSI/ISA-S88.01-1995 5.2.2 Equipment control equipment entities control capability possible different equipment entities important characteristics main basis classification equipment entities. following paragraphs equipment control individual equipment entities discussed. Process cell process cell capable orchestrating processing activities more batches. It receives recipes containing procedure, parameter, other information schedule containing operational requirements each batch. It may also need prepare monitor equipment resources currently involved batch processing, such which units are available, what units piping going through clean-in-place (CIP) routine, what current inventories raw materials are. complexity control within process cell depend equipment available within process cell, interconnectivity among equipment, degree freedom of movements batches through equipment, arbitration use equipment so that equipment can used most effectively. Equipment control process cell may distributed same manner physical equipment subdivided. example, if process cell subdivided into trains, equipment control within process cell may distributed among various trains. Equipment modules control modules may exist separate entities under direct control of process cell. Basic control process cells process cell may include basic control spans several units. example, interlock that shuts unit down may need propagated upstream units feeding this particular unit. Procedural control process cells execution procedure initiation individual unit procedures process cell responsibility. execution may may integral coordination control involved with movement batches described Coordination control process cells More coordination control needed process cells than lower level equipment entities because — process cell may contain multiple units process multiple batches same time. involves coordinating execution number different procedures; — control movement batches may involve number choices between alternate paths. Although these choices may made via links between units, process cell may also have determine routing; — arbitration may needed process cell level optimize use resources, such shared resources resources must reserved well advance time actually needed. Examples coordination control process cell include algorithms that — manage initialization movement batches being processed within process cell; ANSI/ISA-S88.01-1995 33 — initiate and/or associate unit procedures, parameters other information individual units proper order cause them process product described unique combination schedules recipes. Unit Units coordinate functions lower level entities, such equipment modules control modules. primary purpose equipment control unit control processing batch currently associated with unit. Basic control units Basic control unit generally performed regulatory control discrete control equipment modules control modules within unit. Procedural control units Units may include execute equipment phases, equipment operations, equipment unit procedures they may execute recipe operations recipe unit procedures passed it. Coordination control units Equipment control unit include substantially higher level coordination control than any lower level equipment entities. may include, example, algorithms manage unit acquired resources; arbitrate requests services from other units from process cell; acquire services resources from outside unit; communicate with other equipment entities outside unit boundaries. Equipment module primary purpose equipment control equipment module coordinate functions of other equipment modules lower level control modules. equipment module may be commanded process cell, unit, operator, or, some cases, another equipment module. Basic control equipment modules Basic control equipment module generally performed regulatory control discrete control control modules within equipment module. Procedural control equipment modules Equipment modules may execute equipment phases, they do have capability of executing higher level procedural elements. Coordination control equipment modules Coordination control equipment module includes coordination its component parts may include algorithms propagating modes arbitrating requests from units. Control module Equipment control normally found level directly manipulates actuators other control modules. control module can direct commands other control modules actuators if they have been configured part control module. Control process effected through equipment specific manipulation control modules actuators. Examples equipment control control modules include — opening closing valve, with confirmation failure alarms; 34 ANSI/ISA-S88.01-1995 — regulating position control valve based sensor reading PID control algorithm; — setting maintaining state several valves material header. Basic control control modules Control modules contain basic control. Although control normally either regulatory state oriented, some cases it both. It may also include conditional logic. example, open valve if temperature within limits downstream valve open. Regulatory control dedicated maintaining process variable variables near some desired value. Complex control strategies such multivariable control, model-based control, artificial intelligence techniques may also fit into category regulatory control. State-oriented control refers setting state piece equipment opposed state of process variable variables. state-oriented device has finite number states. It defines product independent processing sequence. Control modules may contain exception handling. Procedural control control modules Control modules do perform procedural control. Coordination control control modules Coordination control control module may include, example, algorithms propagating modes arbitrating requests from units usage. 5.2.3 Structuring equipment entities This section discusses general principles involved segmenting process cell into equipment entities can carry out specified processing activities equipment-specific actions. Total explanation process segmentation principles beyond scope this standard. It important note physical process cell design can greatly influence implementation batch control. Minor differences physical system can dramatically affect organization equipment entities procedural elements. All control related sections standard assume process cell question (both physical equipment related control activities) has been subdivided into well defined equipment entities such units, equipment modules, control modules. Effective subdivision of process cell into well-defined equipment entities complex activity, highly dependent individual requirements specific environment which batch process exists. Inconsistent inappropriate equipment subdivisions can compromise effectiveness modular approach recipes suggested standard. Subdivision process cell requires clear understanding purpose process cell's equipment. Such understanding allows identification equipment entities must work together serve identifiable processing purpose. Structuring process cells subdivision process cell usually follows principles listed below : — function equipment entity serves product processing must clear unambiguous. ANSI/ISA-S88.01-1995 35 — function performed equipment entity must consistent terms of processing task, should usable task matter what product being manufactured given time. — Subordinate equipment entities should able execute task(s) independently asynchronously, allowing highest level equipment entity orchestrate activities of its subordinates. — Interactions between equipment entities should minimized. While planned interaction periodically necessary, each equipment entity should perform its functions while influencing functioning other equipment entities little possible. — Equipment entities must have clear boundaries. — consistent basis required definition equipment entities. operator subsequently interacting with similar equipment entities should able do so naturally without confusion. — Necessary interaction between equipment entities is, insofar possible, coordinated by equipment entities same level next higher level. Structuring units definition unit requires knowledge major processing activities, well equipment capabilities. following guidelines apply: — more major processing activities, such reaction crystallization, may take place unit. — Units should defined such they operate relatively independently each other. — unit presumed operate only batch time. Structuring equipment modules definition equipment module requires knowledge specific minor processing activities equipment capabilities. Equipment modules can carry out finite number minor processing activities, such dosing weighing, typically centered around set of process equipment. Collections control modules can defined equipment modules control modules. If collection executes more equipment phases, then it equipment module. 5.3 Recipes This section discusses types recipes covered standard, five categories of information contained recipe how information changes different recipe types, relationship control recipe procedure equipment procedure. Some guidelines recipe transportability also presented. 5.3.1 Recipe types This section discusses types recipes typically found enterprise. recipe entity that contains minimum set information uniquely defines manufacturing requirements specific product. Recipes provide way describe products how those products produced. Depending specific requirements enterprise, other recipe 36 ANSI/ISA-S88.01-1995 types may exist. However, standard discusses only general recipe, site recipe, master recipe, control recipe (see Figure 8). Fundamental practical application recipes concept different parts enterprise may need information about manufacture product varying degrees of specificity, because different recipients information use it different purposes. Therefore, more than type recipe needed enterprise. It should noted whether particular recipe type actually exists, who generates it, where it generated vary from case case from enterprise enterprise. example, enterprise may choose implement more recipe types. Figure 8 — Recipe types General Recipe Site Recipe Master Recipe Control Recipe may be transformed into may be transformed into basis for Batch ID, batch size, in-process, operatorand/or system - generated information Process Cell - specific information Site - specific information Product - specific processing information includes includes includes includes ANSI/ISA-S88.01-1995 37 product may made many different arrangements equipment many different sites. Recipes appropriate site set equipment may appropriate another site set equipment. can result multiple recipes single product. There should be sufficient structure definition recipes allow tracing genealogy given recipe. recipe contains neither scheduling nor equipment control. recipe contains processrelated information specific product. permits batch processing equipment make many different products without having redefine equipment control each product. There substantial difference between general/site recipes master/control recipes. general site recipes describe technique, is, how do it principle. Master control recipes describe task, is, how do it with actual resources. General recipe general recipe enterprise level recipe serves basis lower-level recipes. general recipe created without specific knowledge process cell equipment will be used manufacture product. It identifies raw materials, relative quantities, required processing, without specific regard particular site equipment available at that site. It created people with knowledge both chemistry processing requirements peculiar product question, reflects interests concerns. While general recipe specific equipment particular site, technology for manufacturing product usually have evolved sufficiently beyond laboratory so that equipment requirements can described enough detail define type equipment needed particular site particular set batch plant equipment. general recipe provides means communicating processing requirements multiple manufacturing locations. Quantities may expressed fixed normalized values; equipment requirements are expressed terms attributes needed equipment, such pressure requirements materials construction. general recipe may used basis enterprise-wide planning investment decisions. It may part of, referenced production specifications and, such, used for production planning information customers authorities. Site recipe site recipe specific particular site. It combination site-specific information general recipe. It usually derived from general recipe meet conditions found particular manufacturing location provides level detail necessary site-level, longterm production scheduling. However, it may also created directly without existence general recipe. Such things language which it written local raw material differences are accommodated site-specific variances. It still specific particular set process cell equipment. Typically, site recipe output local "site focused" process development function. There may multiple site recipes derived from general recipe, each covering part general recipe may implemented specific site. Master recipe master recipe level recipe targeted process cell subset process cell equipment. master recipe can derived from general recipe site recipe. It can also created stand-alone entity if recipe creator has necessary process product knowledge. 38 ANSI/ISA-S88.01-1995 Some characteristics master recipes include following: — There may multiple master recipes derived from site recipe, each covering part of site recipe may implemented process cell. — master recipe has sufficiently adapted properties process cell equipment ensure correct processing batch. done combining functionality specific set process cell equipment with information from master recipe. — master recipe, formula data may specified normalized values, calculated values, fixed values. — master recipe may contain product-specific information required detailed scheduling, such process input information equipment requirements. — master recipe level required recipe level, because without it control recipes can created and, therefore, batches can produced. — Whether batch manufacturing equipment operated manually fully automatically, master recipe exists either identifiable set written instructions electronic entity. Control recipe control recipe starts copy specific version master recipe then modified necessary with scheduling operational information specific single batch. It contains product-specific process information necessary manufacture particular batch of product. It provides level detail necessary initiate monitor equipment procedural entities process cell. It may have been modified account actual raw material qualities actual equipment utilized. selection units appropriate sizing can done any time before information needed. Since modifications control recipe can made over period time based scheduling, equipment, operator information, control recipe may go through several modifications during batch processing. Examples include — defining equipment actually used control recipe initiation of batch when it becomes known; — adding adjusting parameters based "as-charged" raw material quality midbatch analysis; — changing procedure based some unexpected event. 5.3.2 Recipe contents Recipes contain following categories information: header, formula, equipment requirements, procedure, other information. following subparagraphs provide details regarding these categories. significant changes from recipe type another noted. Header administrative information recipe referred header. Typical header information may include recipe product identification, version number, originator, issue date, approvals, status, other administrative information. example, site recipe may contain name version general recipe from which it was created. ANSI/ISA-S88.01-1995 39 Formula formula category recipe information includes process inputs, process parameters, process outputs. process input identification quantity raw material other resource required to make product. addition raw materials which consumed batch process manufacture product, process inputs may also include energy other resources such manpower. Process inputs consists both name resource amount required to make specific quantity finished product. Quantities may specified absolute values or equations based upon other formula parameters batch equipment size. Process inputs may specify allowable substitutions, expressed same basic form. process parameter details information such temperature, pressure, time pertinent to product does fall into classification input output. Process parameters may be used set points, comparison values, conditional logic. process output identification quantity material and/or energy expected result from execution recipe. data may detail environmental impact may also contain other information such specification intended outputs terms quantity, labeling, yield. types formula data distinguished provide information different parts enterprise need available without clutter processing details. example, list of process inputs may presented condensed list ingredients recipe set of individual ingredients each appropriate procedural element recipe. Equipment requirements Equipment requirements constrain choice equipment eventually used to implement specific part procedure. general site recipes, equipment requirements typically described general terms, such allowable materials required processing characteristics. It guidance from constraints imposed equipment requirements allow general site recipe to eventually used create master recipe which targets appropriate equipment. master recipe level, equipment requirements may expressed manner specifies allowable equipment process cells. If trains have been defined, then it possible master recipe (and resulting control recipe) based equipment train rather than full range equipment process cell. control recipe level, equipment requirements same as, subset of, allowable equipment master recipe. control recipe may used include specific allocations process cell equipment, such Reactor R-501, when becomes known. Recipe procedure recipe procedure defines strategy carrying out process. general site recipe procedures structured using levels described process model since these levels allow process described non-equipment specific terms. master control recipe procedures structured using procedural elements procedural control model, since these procedural elements have relationship equipment. recipe creator limited use procedural elements have been, be, configured made available use creating procedure. He she may use any combination these procedural elements define procedure. Determination which of these procedural elements may part procedure application specific design decision based many factors including capabilities controls degrees of freedom appropriate recipe creator given application. 40 ANSI/ISA-S88.01-1995 General recipe procedure procedure information general recipe expressed three levels breakdown: Process Stages, Process Operations, Process Actions (see Figure 9). functionality of these levels corresponds functionality analogous levels Process Model (see 4.1.3). process stage, process operation, process action constrained unit boundaries real plant. They describe processing activities others may choose execute or many different units general site recipe transformed run more real plants. Figure 9 — General recipe procedure General Recipe Procedure General Recipe Process Stage General Recipe Process Operation General Recipe Process Action ordered set of ordered set of ordered set of ANSI/ISA-S88.01-1995 41 Site recipe procedure procedure information site recipe consists process stages, process operations, process actions relate directly those defined general recipe. general, there 1:1 correspondence between process stages general recipe process stages site recipe, between process operations general recipe process operations site recipe, between process actions general recipe process actions site recipe. with other site recipe information, process stages, process operations, process actions may modified make recipe site-specific. Master recipe procedure recipe procedure portion master recipe may contain recipe unit procedures, recipe operations, recipe phases (see Figure 10). Figure 10 — Master recipe procedure Recipe Procedure Recipe Unit Procedure Recipe Operation Recipe Phase may ordered set of may ordered set of may ordered set of 42 ANSI/ISA-S88.01-1995 creation procedure master recipe from procedure site recipe may quite complex. master recipe must contain sufficiently detailed equipment requirements information so resources may determined allocated create initiate control recipe. It recipe level set recipe phases necessary carry out intended process actions, process operations, process stages can determined. There may 1:1, 1:n, n:1 relationship between process actions general site recipe recipe phases master recipe, between process operations general site recipe recipe operations master recipe, between process stages general site recipe recipe unit procedures master recipe (see Figure 11). actual relationship may depend equipment being used. Figure 11 — Procedural element relationships site recipe master recipe Although there general similarity between processing intent process actions processing function defined recipe phases, there necessarily one-to-one correspondence between two. process action may correspond several recipe phases, several process actions may correspond single recipe phase. There similar relationship between process operations operations. There significant differences also. Operations carried completion single unit target equipment while process operations constrained units specific facility. single process operation might require more operations carry out processing intent described. There similar relationship between process stages unit procedures there between process operations operations. Unit procedures also carried completion single unit target equipment while process stages constrained equipment boundaries specific facility. single process stage might require more unit procedures carry out processing intent described. Site Recipe Procedure Process Stage Process Operation Process Action Master Recipe Recipe Procedure Recipe Unit Procedure Recipe Operation Recipe Phase ANSI/ISA-S88.01-1995 43 Control recipe procedure procedure control recipe consists recipe unit procedures, recipe operations recipe phases relate directly those defined master recipe. control recipe creation time, there 1:1 correspondence between recipe unit procedures master recipe recipe unit procedures control recipe, between recipe operations master recipe recipe operations control recipe, between recipe phases master recipe recipe phases control recipe. Changes control recipe procedure during execution may cause it differ from master recipe procedure. control recipe, master recipe, procedure divided along unit procedure boundaries provide process cell with processing requirements recipe unit-by-unit basis. Other information Other information category recipe information may contain batch processing support information contained other parts recipe. Examples include regulatory compliance information, materials process safety information, process flow diagrams, packaging/ labeling information. 5.3.3 Control recipe procedure/equipment control relationship control recipe itself does contain enough information operate process cell. It must be linked equipment control actually causes equipment operate make batches. Equipment control considered part recipe. section discusses separation between control recipe procedure equipment control, procedural elements that used control recipe procedure equipment control, mechanism that used link control recipe procedure with equipment control. Control recipe procedure/equipment control separation Figure 12 shows separation between control recipe procedure equipment control. control recipe procedure must contain least procedural element, which recipe procedure. Equipment control must also contain least procedural element provides linkage needed operate physical equipment. example described Figure 12, this assumed equipment phase. control recipe procedure might include recipe unit procedures, recipe operations, recipe phases. Such recipe procedure must then linked (by reference) equipment procedure equipment control if batches executed. Whenever procedural element, such recipe procedure, recipe unit procedure, recipe operation, recipe phase, linked to equipment control, it must exist recipe procedural element (such recipe operation) equipment procedural element (such equipment operation). Whenever recipe phases used control recipe procedure, recipe phases linked equipment phases. When recipe unit procedures, recipe operations, recipe phases used part control recipe procedure, it may still helpful use lower level equipment procedural elements (some all) part equipment control provide modular structure equipment control. 44 ANSI/ISA-S88.01-1995 NOTE – boxes with slashed lines borders highlighted point out these procedural elements may part either control recipe procedure equipment control. Figure 12 — Control recipe procedure/equipment control separation Control recipe/equipment procedural elements following typically associated with recipe procedural elements: — description functionality required — Formula other parameter information specific procedural element — Equipment requirements specific procedural element order recipe procedural element able reference equipment procedural element, it must have identification enables element correctly linked. other cases, it must reference include other recipe procedural elements specification execution order those procedural elements. equipment procedural element linked typically has following: — identification can referenced recipe procedural element higher level equipment procedural element Procedure Unit Procedure Operation Phase Equipment Phase Recipe Procedure [Must Always Exist] Control Recipe Procedure Equipment Control ordered set of ordered set of ordered set of ANSI/ISA-S88.01-1995 45 — description functionality provided — Variables can receive formula other parameter information from recipe — Execution logic It possible recipe creator work with higher level procedural element defining procedure still have lower level procedural elements part procedure. could occur when higher level procedural element has been pre-configured terms more lower level procedural elements. When recipe creator invokes use higher level procedural element, lower level procedural elements carried along, even though they may be invisible recipe creator, become part procedure. When procedural element used more than once recipe, there may need uniquely identify each occurrence procedural element operator batch history. Control recipe procedure/equipment control linking There must some method link control recipe procedural elements with equipment procedural elements. examples below demonstrate linkage between control recipe procedure equipment control when procedural elements from procedural control model used application. This linking done associating recipe procedural elements with equipment procedural elements. way, call certain processing function separated from equipment control. It also enables same recipe procedural element use different equipment procedural elements, depending what equipment recipe addresses. equipment phase may initiated things other than execution control recipe. It may initiated request another unit request operator. independent execution phase may useful handling exception conditions, during start-up or maintenance, and/or prepare unit production. If unit procedures, operations, phases part control recipe procedure, linking (by reference) control recipe procedure equipment control done phase level (see Figure 13). drawing applies control recipe. 46 ANSI/ISA-S88.01-1995 Figure 13 — Control recipe procedure example with unit procedures, operations, phases Equipment Phase Recipe Procedure Control Recipe Procedure Recipe Unit Recipe Operation Procedure Recipe Phase references Equipment Control ordered set of ordered set of ordered set of ANSI/ISA-S88.01-1995 47 If phases do exist part control recipe operations do, linking would done at operation level (see Figure 14). example applies control recipe. Figure 14 — Control recipe procedure example with unit procedures operations Equipment Phase Equipment Operation Recipe Procedure Control Recipe Procedure Recipe Unit Recipe Operation Procedure references Equipment Control ordered set of ordered set of ordered set of 48 ANSI/ISA-S88.01-1995 If neither phases nor operations exist part control recipe unit procedures do, linking would done unit procedure level (see Figure 15). example applies control recipe. Figure 15 — Control recipe procedure example with unit procedures Equipment Phase Equipment Operation Recipe Procedure Unit Equipment Procedure Recipe Unit Procedure references Control Recipe Procedure Equipment Control ordered set of ordered set of ordered set of ANSI/ISA-S88.01-1995 49 If only procedure exists part control recipe, linking would done procedure level (see Figure 16). example applies control recipe. Figure 16 — Control recipe procedure example with only procedure Control recipe procedure/equipment control collapsibility preceding examples have assumed levels procedure model being used. with other models standard, procedural control model collapsible. Levels procedural control model may left out specific application. Some examples discussed below. If procedure addresses single unit, procedure itself may take place unit procedure, recipe procedure has collapsed (see Figure 17a). Recipe phases alone might used define recipe procedure addresses single unit. Then recipe procedure consists phases needed accomplish function procedure strategy needed organize properly sequence phases. procedure model collapsed eliminate use unit procedures operations overtly stated subdivisions (see Figure 17b). same collapsing may happen with equipment procedure, shown Figure 17c, where no unit procedures, operations, phases used recipe procedure, such when recipe procedure has been collapsed just procedure name, unit procedures or Equipment Phase Equipment Operation Recipe Procedure Unit Equipment Procedure Equipment Procedure references Control Recipe Procedure Equipment Control ordered set of ordered set of ordered set of 50 ANSI/ISA-S88.01-1995 operations used equipment procedure. So now equipment procedure made up of ordered set equipment phases. phase level may omitted if specific application better described with operations that are further subdivided. Then operation interacts directly with basic control (see Figure 17d). Figure 17 — Control recipe procedure/equipment control collapsibility examples references Recipe Procedure ordered set of ordered set of Recipe Phase references Recipe Operation Recipe Procedure Recipe Phase ordered set of ordered set of Equipment Phase references references (a) (c) (b) (d) Recipe Procedure Recipe Unit Procedure Recipe Operation Equipment Procedure Recipe Procedure Equipment Phase ordered set of ordered set of Equipment Operation Equipment Phase ANSI/ISA-S88.01-1995 51 following considerations must taken into account when collapsing: — When procedural element level taken out, next higher level must take over its functions contain ordering logic controlling next lower level other information would have been stated collapsed level, including equipment requirements other information. — lowest level equipment procedural control must have functionality activate equipment through basic control. 5.3.4 Recipe transportability Recipe transportability ensures recipe information movement possible between batch control implementations same recipe level. recipe information must understood by each implementation. general recipe transportable from it was created site. site recipe transportable, same extent general recipe. It intended used within specific site transportable within site. master recipe transportable another process cell, recognizing master recipe has been customized particular set process cell equipment. When master recipe transported another process cell, some process engineering analysis may necessary to — determine new set process cell equipment configured similarly so master recipe can used unchanged or; — make necessary changes so modified master recipe run target set process cell equipment. control recipe transportable. 5.4 Production plans schedules Production plans schedules state production requirements enterprise, sites, areas, process cells. Since these levels physical model operate different time horizons, number different types plans schedules typically needed within enterprise. detailed discussion various types plans schedules outside scope standard. Only scheduling needs process cell level, batch schedule, will discussed. batch schedule typically contains more detailed information than production plans schedules aimed higher levels enterprise. It contains information such products that produced, how much each product produced, when they are required specific process cell. It identifies which batches made, order, equipment used. schedule also deals with issues such personnel requirements, raw material options, packaging requirements. Time horizons batch schedule dependent speed processes might be measured minutes, hours, shifts, days. batch schedule based specific resources requirements process cell. possible paths equipment options are determined point. batch schedule totally meaningful, schedule would need redone time there significant variance from time projections, resource assumptions, other anticipated factors which schedule was based. example, schedule may have updated if activity completed close scheduled time. Whether activity delayed whether it completed ahead time, primary concern 52 ANSI/ISA-S88.01-1995 whether activity can affect other schedules process cell other associated process cells. following typical information found batch schedule: — Product name — Master recipe name — Quantity (with engineering units) product — Equipment materials permitted used, such path raw material — Projected mode operation — Order initiation priority — Lot ID (if preassigned) — Batch ID (if preassigned) — Projected start time end time — Disposition finished batch — Specific customer requirements key efficient batch manufacturing comprehensive method links various plans schedules with batch data collection. Batch data collection source timely information provides feedback so these plans schedules can fine tuned. During actual manufacturing batch, information needed real time so schedules can be updated within short time horizon. update information also allows user kept apprised status lots and/or batches schedule. 5.5 Production information This section discusses information generated course production. Information needs collected made available various levels enterprise. type of information needed varies between different parts enterprise. enterprise level, for example, summary information may needed. Examples include amount of production particular product was achieved specific site sites, how much product available inventory. Process development may need detailed processing information individual batches order perform statistics comparisons. process cell level batches are actually executed, there need more detailed information order monitor day-to-day production, perform adjustments schedule, adjust processing from batch batch. Production information may batch specific it may common several batches produced. 5.5.1 Batch-specific information batch-specific information may include following: — copy control recipe was used make batch. may identical to original recipe because operator changes, equipment problems, etc. It may be desirable record both original recipe actual recipe. ANSI/ISA-S88.01-1995 53 — Recipe data. actual process data corresponds exactly recipe formula, such amount type material charged. can then compared original recipe. — Recipe-specified data. data whose collection specified recipe. example process control information trended. — Summary batch data. data such utilities consumption, equipment run times, temperatures entire batch. — Operator comments — Continuous data. process data collected independent specific events within batch with purpose giving accurate history measurement. — Event data. data from predictable unpredictable events, such recording start stop times procedural elements, unpredictable process equipment events. — Operator data. includes operator intervention may affect processing of batch (includes operator's ID). — Analysis data. data related off-line measurements analyses such measured variables, operator ID, lab technician ID, time entry results, time of sample. 5.5.2 Common (non-batch specific) batch information Examples common (non-batch specific) batch information include: — Quality control information. information related monitoring raw material qualities processing quality. — Utility systems information. process information equipment such process heating cooling do produce batches themselves support equipment that does produce batches. — Equipment history. historical information, such equipment utilization, calibration, maintenance. — Operational documentation. includes documentation such production volumes, material consumption summaries, inventory statistics. — Materials information. typically information such quality information packaging labeling information input output materials. 5.5.3 Batch history All recorded information pertaining batch referred batch history. batch history typically include batch-specific information. Common (non-batch specific) batch information may included batch history. Since information nature typically applies to several batches being processed process cell, it may included individual batch histories reference. many regulated industries, record batch history important product itself. Without reliable accurate batch record keeping, product quality traceability cannot be ensured. Complete batch record keeping also provides information invaluable process analysis continuous improvement efforts. Batch history must stored way makes it possible associate data with batch (or batches) which it relates processing has taken place. means that, 54 ANSI/ISA-S88.01-1995 addition specific batch identity, data must associated with actual execution appropriate procedural elements, relevant. structure executed procedure may differ from what specified original recipe because operator intervention, exception handling, even planned diversity procedure, such changes caused varying resource limitations. 5.5.4 Batch reports extraction data related more batches called batch report. extraction ordering data report may vary based intended recipient batch report. Some typical recipients batch reports types information typically included their reports are — production management: These batch reports typically provide key economic information processing result resource utilization from multiple batches. — product development: These batch reports typically include detailed process information for individual batch compare similar data between group batches. — plant operations: These batch reports typically include data collected current point processing. — quality management: These batch reports typically contain information documenting batch quality, which may useful quality statistics. — authorities: These batch reports typically provided documentation production complying with regulations. — customers: These batch reports usually documentation product quality process uniformity. 5.6 Allocation arbitration This section discusses mechanisms allocating resources batch unit arbitrating use common resources when more than requester needs use common resource at same time. Resources such equipment assigned batch unit they needed complete or continue required processing. Allocation form coordination control makes these assignments. When more than candidate allocation exists, selection algorithm such "select lowest duty time" might used basis choosing resource. When more than request single resource made, arbitration needed determine which requester will be granted resource. algorithm such "first come/first served" might used basis for arbitration. following sections, allocation arbitration discussed terms equipment. concepts apply equally well other resources, such operators. 5.6.1 Allocation very nature batch processing requires many asynchronous activities take place relative isolation from each other with periodic points synchronization. Many factors, both expected unexpected, can affect time required more asynchronous activities from point synchronization next. those reasons, because inherent variation manufacturing process, exact equipment which available at time it needed very difficult predict over significant period time. Even though ANSI/ISA-S88.01-1995 55 schedule may have been planned totally optimize processing sequence from standpoint equipment utilization, it often desirable allow alternate equipment used if units planned batch available when planned. case allocation units to batch -- routing path batch -- decision which must made every time there more than path batch can take through available equipment. If more than unit can acquire request services single resource, resource designated common resource. Common resources often present with complex batch processes. Common resources often implemented either equipment modules control modules. common resource may either exclusive-use shared-use. If resource designated exclusive-use, only unit may use resource time. shared weigh tank batch plant might example exclusive-use resource. It can be used only reactor time. schedule some other basis allocation must take this exclusive-use resource into consideration. If reactor waiting use weigh tank while another using it, waiting reactor idle making product, which has negative effect equipment utilization. If common resource designated shared, several units may use resource same time. Some shared-use resources batch plant might process heater serving multiple units same time raw material distribution system which capable delivering material more than unit time. If capabilities shared-use resource limited, then it possible requests service might exceed capacity resource. that case some same concerns about allocation which apply exclusive-use resources also apply shared-use resources. Care must also taken so unit does improperly shut off deactivate resource while other units using it. 5.6.2 Arbitration If there multiple requesters resource, arbitration required so proper allocations can made. Arbitration resolves contention resource according some predetermined algorithm provides definitive routing allocation direction. algorithm may take various forms such predetermined schedule with reservations, batch priority scheme, it might rely upon operator judgment. Arbitration may bring with it two distinct issues which affect complexity, resource reservation preemption. Reservation allows claim placed resource prior actual allocation. Reservation allows arbitration based future needs rather than allowing first request allocation of idle resource take precedence regardless priority. Preemption occurs when higher priority batch allowed cancel interrupt use resource assigned lower priority batch. When allowed, it most often associated with allocation exclusive-use common resource can apply allocation resource. 5.7 Modes states This section discusses modes states equipment entities procedural elements. preceding sections, models describing equipment entities procedural elements have been defined. these models, transitions procedural elements equipment entities occur within each hierarchical level. status equipment entities procedural elements may described modes states. Modes specify manner which these transitions take place; states specify current status. Other resources, such materials, may also have states. 56 ANSI/ISA-S88.01-1995 5.7.1 Modes Equipment entities procedural elements may have modes. Example modes described this standard relation batch control. mode equipment entity may based procedural elements equipment entities utilizing basic control functions, depending main control characteristic entity. This standard uses examples three modes (automatic, semi-automatic manual) for procedural elements, two modes (automatic manual) equipment entities. Control modules contain basic control functions have automatic manual modes, whereas unit running procedural control would also have semi-automatic mode. This standard does preclude additional modes require use modes defined here. functionality modes presented felt generally useful most batch applications. By naming modes including them standard, defined set terms documented that can used when communicating batch control issues. mode determines how equipment entities procedural elements respond commands how they operate. case procedural elements, mode determines way procedure progress who can affect progression. case control module, such automatic block valve, contains basic control functions, mode determines mechanism used drive valve position who/what, such another device operator, may manipulate it change its state. For procedural elements, mode determines way transitions treated. automatic mode, transitions take place without interruption when transition conditions are fulfilled. semi-automatic mode, procedure requires manual approval proceed after transition conditions fulfilled. Skipping re-executing more procedural elements, without changing order, usually allowed. manual mode, procedural elements order execution specified manually. For equipment entities containing basic control functions, mode determines how states may manipulated. automatic mode equipment entities manipulated control algorithms manual mode equipment entities manipulated operator. Table 1 lists possible behaviors commands associated with example modes. Equipment entities procedural elements may change mode. change can occur if conditional logic requirements change met internal logic external command such generated another procedural element operator. mode change takes place only when conditions change request met. change mode equipment entity type procedural element type may cause corresponding changes other types. example, putting unit procedure Semiautomatic mode may cause lower-level procedural elements unit go Semiautomatic mode, or, safety interlock trip may cause several control modules go Manual mode with outputs minimum value. propagation can either direction, from higher level entity lower level entity, conversely. standard does specify propagation rules. ANSI/ISA-S88.01-1995 57 Table 1 — Possible implementations example modes 5.7.2 States Equipment entities procedural elements may have states. Example states described this standard relation batch control. state completely specifies current condition of equipment entities procedural elements. case valve, state may "percent open," case procedural element, it may "running" "holding." This standard uses example self-consistent set procedural states commands. number possible states commands names vary equipment entities for procedural elements. Examples states procedural elements include running, holding, paused, stopped, aborted, complete. Examples states equipment entities include on, off, closed, open, failed, travelling, tripped, 35% open, available. Examples commands applicable procedural elements start, hold, pause, stop, abort. This standard does require these states preclude additional states. functionality states commands presented felt generally useful most batch applications. By naming states commands including them standard, defined set terms documented can used when communicating batch control issues. Equipment entities procedural elements may change state. change can occur if conditional logic requirements change met internal logic external command such generated another procedural element operator. change state equipment entity type procedural element type may cause corresponding changes other types. example, putting unit procedure Held state may cause procedural elements unit go Held state, or, safety interlock trip may cause procedural elements unit go Aborting state. propagation can be either direction, from higher level entity lower level entity, conversely. This standard does specify propagation rules. Mode Behavior Command Automatic (Procedural) transitions within procedure are carried out without interruption appropriate conditions met. Operators may pause progression, but may force transitions. Automatic (Basic Control) Equipment entities manipulated by their control algorithm. equipment cannot manipulated directly operator. Semi-automatic (Procedural Only) Transitions within procedure carried out manual commands appropriate conditions fulfilled. Operators may pause progression or re-direct execution appropriate point. Transitions may be forced. Manual (Procedural) procedural elements within procedure are executed order specified by operator. Operators may pause progression or force transitions. Manual (Basic Control) Equipment entities manipulated by control algorithm. Equipment entities may manipulated directly operator. 58 ANSI/ISA-S88.01-1995 set procedural states commands provided below representative example to illustrate way define these procedural states commands. list states commands summarized state transition matrix (see Table 2). example state transition diagram derived from matrix first three lines matrix (Idle, Running, Complete) (see Figure 18). Table 2 — State transition matrix example states procedural elements NOTE – states ending with "ING" transient states. If logic completes normally, then state transition state listed under COMMAND END STATE occurs. example, if RUNNING state completes normally, then state automatically transitions COMPLETE. Execution transient states (ending -ING) governed mode. Command Start Stop Hold Restart Abort Reset Pause Resume Initial State No Command End State State Transition Matrix Idle Running Running Complete Stopping Holding Aborting Pausing Complete Idle Pausing Paused Stopping Holding Aborting Paused Stopping Holding Aborting Running Holding Held Stopping Aborting Held Stopping Restarting Aborting Restarting Running Stopping Holding Aborting Stopping Stopped Aborting Stopped Aborting Idle Aborting Aborted Aborted Idle ANSI/ISA-S88.01-1995 59 NOTE – state transition diagram derived from first three initial states state transition matrix Table 2 (Idle, Running, Complete) Figure 18 — State transition diagram example states procedural elements Procedural states For example, list valid procedural states following: — IDLE: procedural element waiting START command cause transition RUNNING state. — RUNNING : Normal operation — COMPLETE: Normal operation has run completion. procedural element now waiting RESET command cause transition IDLE. — PAUSING: procedural element equipment entity has received PAUSE command. cause procedural element stop next defined safe stable stop location its normal RUNNING logic. Once stopped, state automatically transitions PAUSED. — PAUSED: Once procedural element has paused defined stop location, state changes PAUSED. state usually used short-term stops. RESUME command causes transition RUNNING state, resuming normal operation immediately following defined stop location. — HOLDING: procedural element has received HOLD command executing its HOLDING logic put procedural element equipment entity into known state. If sequencing required, then procedural element equipment entity transitions immediately HELD state. Restarting Running Abort Stop Aborting Reset Reset Start Pause Hold Resume Restart Reset Stopping Idle (Initial State) Holding Pausing Paused Complete Aborted Stopped Held Final States Quiescent States Transient States 60 ANSI/ISA-S88.01-1995 — HELD: procedural element has completed its HOLDING logic has been brought to known planned state. state usually used long-term stop. procedural element equipment entity waiting further command proceed. — RESTARTING: procedural element has received RESTART command while HELD state. It executing its restart logic order return RUNNING state. If no sequencing required, then procedural element equipment entity transitions immediately RUNNING state. — STOPPING: procedural element has received STOP command executing its STOPPING logic, which facilitates controlled normal stop. If sequencing required, then procedural element equipment entity transitions immediately STOPPED state. — STOPPED: procedural element has completed its STOPPING logic. procedural element equipment entity waiting RESET command transition to IDLE. — ABORTING: procedural element has received ABORT command executing its ABORT logic, which logic facilitates quicker, necessarily controlled, abnormal stop. If sequencing required, then procedural element transitions immediately ABORTED state. — ABORTED: procedural element has completed its ABORTING logic. procedural element waiting RESET command transition IDLE. Commands For example, list valid commands following: — START: command orders procedural element begin executing normal RUNNING logic. command only valid when procedural element IDLE state. — STOP: command orders procedural element execute STOPPING logic. This command valid when procedural element RUNNING, PAUSING, PAUSED, HOLDING, HELD, RESTARTING state. — HOLD: command orders procedural element execute HOLDING logic. This command valid when procedural element RUNNING, PAUSING, PAUSED RESTARTING state. — RESTART: command orders procedural element execute RESTARTING logic safely return RUNNING state. command only valid when procedural element HELD state. — ABORT: command orders procedural element execute ABORTING logic. command valid every state except IDLE, COMPLETED, ABORTING ABORTED. — RESET: command causes transition IDLE state. It valid from COMPLETE, ABORTED, STOPPED states. — PAUSE: command orders procedural element pause next programmed pause transition within its sequencing logic await RESUME command before proceeding. command only valid RUNNING state. ANSI/ISA-S88.01-1995 61 — RESUME: command orders procedural element has PAUSED programmed transition result either PAUSE command SINGLE STEP mode to resume execution. command only valid when procedural element PAUSED state. 5.8 Exception handling event which occurs outside normal desired behavior batch control commonly called exception. Handling these exceptions can occur levels control activity model may part procedural, basic, coordination control. Exception handling essential function batch manufacturing. Exception handling integral part control typically constitutes very large portion control definition. Examples events may indicate need exception handling are — unavailability raw materials, utilities, plant equipment when needed; — product process problems; — control equipment malfunction; — hazardous conditions such fire chemical spills. From standpoint control, exception handling different from desired control strategies event detected, evaluated, response generated. Exception response functions may affect modes states equipment entities of procedural elements. example, high pressure reactor could lead exception response function transferring process STOPPED state, operator could detect some unusual condition initiate similar action. 6 Batch control activities functions This section discusses control functions associated with batch processing, manufacturing, control tasks described previous two sections. control functions defined section elaborate control tasks defined Section 5.1 equipment entities discussed Section 5.2, which bottom levels Physical Model described Section 4.2. Control functions meet control needs higher levels Physical Model also described. convenience purposes, these control functions have been grouped into, discussed context of, control activities. control activities that discussed section Recipe Management, Production Planning Scheduling, Production Information Management, Process Management, Unit Supervision, Process Control, Personnel Environmental Protection. intent section clearly identify individual functionality associated with batch control. make it easier define requirements batch control given application. 62 ANSI/ISA-S88.01-1995 6.1 Control activities Many control functions must implemented successfully manage batch production. These control functions define how equipment batch manufacturing plant controlled. They are needed support equipment entities described previously. They combined into seven control activities, represented Control Activity Model Figure 19. 6.1.1 Control activity model Control Activity Model Figure 19 provides overall perspective batch control shows main relationships between various control activities. It intended show all relationships. These relationships achieved via information flow between control activities. purpose drawing simply show there relationship to define relationship. definition these relationships take place later section control functions grouped within each control activity discussed. few relationships shown Figure 19 discussed further standard. control activities shown relate real needs batch manufacturing environment. need have control functions can manage general, site, master recipes implies need for Recipe Management control activity. Production batches must occur within time domain planned subsequently carried out. Production Planning Scheduling control activity these control functions discussed. Various types production information must available, collection storage batch history necessity. Production Information Management control activity model covers these control functions. Control recipes must generated, batches must initiated supervised, unit activities require coordination, logs reports must generated. These control functions fall under Process Management control activity model. There many control functions needed Unit Supervision control activity level. example, there need allocate resources, supervise execution procedural elements, coordinate activities taking place Process Control level. Process Control, control functions discussed deal directly with equipment actions such need implement control functions using regulating devices and/or state-oriented devices. ANSI/ISA-S88.01-1995 63 Figure 19 — Control activity model Finally, safety personnel surrounding communities must prime concern, along with protection environment. Personnel Environmental Protection control activity covers these control functions. 6.1.2 Information handling dimension control activity model its description information flow throughout levels. such, there number information handling functions can applied all categories data addressed control activity model. These applicable regardless of combination manual computerized systems established site. Additional information handling aspects specific particular control activity described within their respective sections. Production Planning Scheduling Recipe Management Process Management Unit Supervision Process Control Personnel Environmental Protection Outside scope of standard Production Information Management 64 ANSI/ISA-S88.01-1995 Reference information batch manufacturing enterprise may incorporate activities fall outside scope this standard. Examples include — material inventory management; — process product development; — customer service support; — regulatory reporting process validation; — inter-departmental coordination, such production versus support services. To provide interface these information sources, control activities discussed this section need store information way provides usable, accessible data source these external activities. Similarly, each control activity should have ability access relevant reference information needed fulfill its function. Examples reference information include — sales marketing data, including customer orders other statements product demand; — raw material vendor data; — final products specifications; — costing data; — research development data; — standard consumptions raw materials standard yields products manufactured; — rate information various process cells; — equipment capability specifications; — operational procedures equipment maintenance process safety; — human resource information; — quality control information such procedure used perform particular laboratory analysis; — regulatory requirements. Reference information may enterprise-wide, site-wide, area-wide, process cell-wide. Security Within control environment, information used impact control functions, to communicate between levels entities, provide communication control functions outside control activity model. Access information restricted ensure only authorized and/or qualified resources can affect information. Availability Control activity information should stored retrieved way provides necessary safeguards ensure access critical data. time necessary recover access data case loss location should considered carefully. These considerations vary based ANSI/ISA-S88.01-1995 65 different levels control activity model, types information, level detail required. Archival Removal information from control activity into long-term archive often desirable to improve storage efficiency recoverability. Once archived, it should possible retrieve archived data usable form. example, once master recipe longer active use, it would useful able extract information (both structural historical) related that master recipe from main repository. Change management Information defines control — including configuration equipment control recipes — may subject formal change management. Means may provided support — requests authorization changes; — version numbering documentation; — validation changes; — audit tracking. Change management may also include restrictions checks necessary maintain integrity configuration. example, it may necessary prevent recipe creator from modifying procedural element use active recipe. Reference tracking Historical tracking information references — example, which definitions used within which others which served basis others — can important analysis production performance demonstrating compliance with production guidelines. function can also provide means attach written comments about changes, assist subsequent interpretation. 6.1.3 Process control engineering order required processing functions properly carried out batch manufacturing environment, equipment structure needed, process functionality, exception handling equipment have fully developed. requires coordinated engineering effort continues from initial definition through life batch processing facility. This section describes process control engineering needed design controls needed support recipe hierarchy, definition equipment capability, development functionality required procedures produce batch. Process control engineering needed general site recipe levels describe procedures, process stages, process operations, process actions master recipe level describe recipe procedures, recipe unit procedures, recipe operations, recipe phases. precise definition appropriate procedural elements equipment entities iterative process. dual work process illustrated Figure 20. Considerations affecting decision process also affect other. Processing considerations primary input definition (or selection) procedural elements characterize functionality associated equipment entities. Since functionality defined affected equipment used, equipment considerations must secondary input. same way, equipment considerations form primary input processing considerations secondary input when making definition (or selection) equipment entities. 66 ANSI/ISA-S88.01-1995 Figure 20 — Simultaneous definition/selection procedural elements equipment entities Recipes can constructed using these procedural elements specific product information. equipment entities arranged into path determined scheduling taking into account arbitration constraints. combination results these activities provides framework within which batch material can manufactured. Process control engineering also includes development revision equipment phases corresponding recipe phases used define recipe. far possible, recipe equipment phases should defined such reasonable functionality unit can expressed terms these phases. They should generally tailored set of known recipes. Then, new recipes can most cases written using existing recipe phases that reference existing equipment phases. development revision recipe equipment phases ongoing activity provides ongoing support batch manufacturing facilities. activity result ongoing drive continuous improvement periodic addition new process technology. 6.2 Recipe management Recipe Management made up control functions create, store, maintain general, site, master recipes. overall output control activity master recipe made available Process Management, which uses it create control recipe. Recipe Management discussed terms managing three levels recipes defining procedural elements used recipe procedures (see Figure 21). Specific Product Requirements Scheduling / Arbitration Constraints Recipe Processing Considerations Equipment Considerations Define / Select Procedural Elements to Match Equipment Entities Define / Select Equipment Entities To Match Procedural Elements Path Manufacture of Batch ANSI/ISA-S88.01-1995 67 Figure 21 — Recipe management 6.2.1 Manage general recipes Manage general recipes control function which general recipes created, maintained stored. specific processing requirements furnished process development activity for product being considered serve basis general recipe. connection with definition individual general recipe, following capabilities may be required: — Selecting combining procedural elements create general recipe procedure — Incorporating formula information — Specifying equipment requirements other information — Maintaining general recipe — Managing changes general recipes Manage General Recipe General Recipe Define General Recipe Procedural Element Define Master Recipe Procedural Element Procedural Element Master Recipe Procedural Element General Recipe Site Recipe Master Recipe Process Management Manage Site Recipe Manage Master Recipe General Recipe Procedural Element Information General Recipe Procedural Element 68 ANSI/ISA-S88.01-1995 6.2.2 Define general recipe procedural elements define general recipe procedural elements control function creates, maintains makes available subsequent use, procedural elements used building blocks general recipe site recipe procedures. procedural elements defined control function may process actions, process operations, process stages, and/or entire general recipe procedure. levels of procedural elements need defined. This control function defines general recipe procedural elements based processing strategies required different products described process development. This information then made available define master recipe procedural elements control function. way, process intent general recipe procedural elements may known at master recipe level. strategies have interpreted transformed into procedural elements enable flexible modular construction general recipes. broader range products can utilize these modular process activity descriptions, easier it to create general recipe. More importantly, modular process actions, process operations, process stages, and/or complete procedures frequently reused tend make recipe transformations lower levels much easier accomplish recipes more consistent. This procedural element information then made available define master recipe procedural elements control function. way, process intent general recipe procedural elements may known master recipe level. connection with definition individual general recipe procedural elements, following capabilities may required: — Naming individual procedural elements — Specifying parameter variables — Describing intended processing functionality — Combining lower level procedural elements specifying sequence execution — Creating, modifying, archiving general recipe procedural elements — Maintaining inventory procedural elements available — Managing changes procedural elements 6.2.3 Manage site recipes Manage site recipes control function which site recipes created, maintained stored. site recipe created combining information appropriate general recipe with site specific information. If additional alternate procedural elements required, only those defined under define general recipe procedural elements control function used. 6.2.4 Manage master recipes Manage master recipes control function which master recipes created, maintained stored. Master recipes defined based specific processing requirements product question. These specific processing requirements may expressed general or site recipe. transformation site recipe into master recipe may complex task. creation of procedure, based predefined procedural elements, must match intent site recipe procedure. Transformation (or creation) content formula follows same general logic used map process actions recipe phases. batch size fixed, range ANSI/ISA-S88.01-1995 69 of batch sizes permissible recipe established, if there constraints degree of scaleability. Formula information adjusted accordingly. equipment requirements are transformed into requirements can verified against actual target equipment. connection with definition individual master recipe, following capabilities may be required: — Selecting combining procedural elements create master recipe procedure — Incorporating formula information — Specifying equipment requirements other information — Creating, modifying, archiving master recipes maintaining recipe headers — Maintaining inventory master recipes — Managing changes master recipes 6.2.5 Define master recipe procedural elements define master recipe procedural elements control function creates, maintains makes available subsequent use, procedural elements used master recipe procedures. These become building blocks master recipe procedure. master recipe procedural elements must reflect processing capabilities required by master recipes. If these generated from general site recipes, then process stages, process operations, process actions map into unit procedures, operations, phases. This control function defines relationship between process actions phases, between process operations operations, between process stages unit procedures. It also defines general scope procedures, unit procedures, operations, phases allow maximum consistent use pre-defined procedural elements across range products be made facility. master recipe procedural elements must, least recipe phase level, able to reference equipment procedural elements when derived control recipe executed. close coordination with engineering equipment procedural elements must therefore take place, ensuring recipe procedural elements adequately reflect control capabilities of target equipment. If required, new functionality made available through creation new procedural elements, along with associated control equipment modifications (see 6.1.3). addition providing building blocks master recipe procedure, control function may also define constraints configuration master recipes, such rules allowable order recipe phases limitations recipe creator's right use recipe phases building blocks. determination such constraints must made based many factors, such safety, complexity recipe creator's task, required flexibility, validation of individual procedural elements. connection with definition individual procedural elements, following capabilities may required: — Naming individual procedural elements — Specifying parameter variables — Describing intended processing functionality — Combining lower level procedural elements specification sequence of execution 70 ANSI/ISA-S88.01-1995 — Creating, modifying, archiving master recipe procedural elements — Maintaining inventory procedural elements available — Managing changes procedural elements 6.3 Production planning scheduling Production Planning Scheduling high level control activity peer level with Recipe Management Production Information Management. It decision process associated with producing batch schedule provided Process Management. Although several control functions would need collected together make up control activity, most of those control functions outside scope standard. section consider only of these control functions: Develop batch schedules. develop batch schedules control function accepts inputs from sources such other types of schedules, master recipes, resource databases, and, based upon scheduling algorithm (automated manual), develops batch schedule (see 5.4 list typical information batch schedule). following capability typically included control function: — Developing batch schedule based information from appropriate source some scheduling algorithm — Developing revised batch schedule demand based significant changes batch progress process cell status information provided Process Management — Allowing manual intervention into scheduling process — Determining availability resources input into scheduling process — Providing procedure method batch sizing along with means organize production batches — Determining feasibility schedule based target equipment 6.4 Production information management Production Information Management high level control activity peer level with Recipe Management Production Planning Scheduling. It control activity involved collecting, storing, processing, reporting production information. non-batch-related use production information dealt with section, actual applications management batch-related information non-batch-related information may very well integral. Both batch-related non-batch-related information may used input higher-level control functions such generation production reports to management. These activities modeled standard. Although several control functions would need collected together make up control activity, most those control functions outside scope standard. section will consider only these control functions: Manage batch history. Batch history collection data related batch. It may organized more files or tables per batch, it may present part database retrievable via key fields, etc. ANSI/ISA-S88.01-1995 71 Batch history built up entries. entry portion information batch representing value set values describing event, logged into batch history action. Manage batch history control function typically includes following capabilities: — Receiving storing information from other parts overall batch control application batches — Manipulating historical data — Producing batch reports manage batch history control function performed regardless equipment used or when batch produced. example, lab data often may added after execution batch. 6.4.1 Receiving storing batch history information entering data from outside into batch history initiated from Process Management, Unit Supervision, Process Control. General collection storage guidelines All data batch history should collected stored way includes gives simple access to — batch identification; — absolute time stamp (Real time); — identification procedural elements with which data associated; — time relative start end batch execution procedural element; — equipment-independent entry identification; — equipment utilized. Adequate storage capacity needed required number batch histories. should include sufficient capacity store batch histories running batches, finalized batches until appropriate actions have been taken (reports printed, long term backup whatever action specified). To extent storage time requirement exceeds storage capacity manage batch history, capability must exist export batch histories onto long-term storage media or external systems. It must possible retrieve these batch histories further extraction of data. Reports displays batch archive (number batches archive, amount data, status [finalized, printed, archived long term archive, etc.]). Reliability batch history entries requirements reliability vary from application application between different entry types. following, number issues reliability described. each type of entry, appropriate level reliability must selected match needs individual application. Reliability issues include — access control: control access data-gathering system, including configuration actual data collected; 72 ANSI/ISA-S88.01-1995 — audit trail: identification manipulation happened with each individual piece of information — including identification person controls involved, time and, some cases, explanation; — logging reliability: specification required reliability logging. Three levels may be distinguished: a) Nice have — specific action case failure. Examples include data for optimization, equipment reliability statistics, etc.; b) Limited holes acceptable if failure indicated batch history (logging absent from . . . . . .); c) Critical — data must available. If it missing, then backup procedures must be possible (electronic manual backup, possibility reconstruction, etc.). importance exact logging latter type information may equivalent to achieved product quality, either financial reasons (accounting) or product safety/responsibility reasons. Therefore receiving function must capable providing feedback information general status receiving function (as well specific confirmation feedback each entry to control activity performs logging) enabling them perform buffering, redundancy reintegration activities or, if required allowed, hold up process. — level detail: level should well defined recipe, it should related to process cell parts process cell. It must possible see if entry absent because corresponding event did occur because it below selected level of detail. — logging actual historic information: Batch history entries should, largest possible extent, reflect actual physical/chemical events influence batch, only what was anticipated recipe. means character amount data logged will vary due variations batch production. — long-term consistency: extent which interpretation batch data relies information outside batch history, such cross reference lists between actual tags batch entry tags names variables, should well described. Such information should stable long term. If changes modifications do occur, then versions that relevant time processing should stored use data retrieval. — speed collection: Speed collection should considered critical factor. order to analyze reasons abnormal conditions, it important system be capable recording events actions precise order which they occurred. Batch material tracing collection batch histories can support batch material tracing if it has complete overview batches, including equipment utilized identification raw materials. Batch history provides backwards tracing if certain end product batch history can traced back involved processes, equipment, ingredients (and involved processes, equipment, ingredients these ingredients). Forward tracing available if consequences certain event usage certain raw material can traced end products affected. ANSI/ISA-S88.01-1995 73 Logging from process management Process Management logging should include information associated with initiating routing batch, equipment-independent information associated with batch. includes — master recipe: master recipe from which control recipe was derived — either copy reference. case reference, master recipe should maintained unchanged long reference may called. — Process Management events control recipe information: information any changes execution control recipe. includes information such equipment allocation start times batches unit procedures. — operator comments: narrative descriptions comments based operators' observations batch processing. information entry should capable being recorded with operator's identification. Logging from unit supervision process control This data could dedicated single batch several batches, such data from shared resources, utility systems, etc. latter case data should available required batch histories. includes: — continuous data: Continuous data defined process data collected independent specific events within batch, with purpose giving accurate history measurement. — pre-specified batch data: data specified logged during execution control recipe. specification data may come from recipe pre-configured. This would include such things total feed reactor mixing time. — predictable events: events expected occur, such start stop times of procedural elements. — unpredictable events: Unpredictable event data defined single point entry based unpredictable process physical condition within batch. includes such items process alarms, equipment failures other upset conditions. case of process alarms, historical data may include following: a) Time activation b) Time acknowledgment c) Time disappearance alarm condition d) Alarm limit e) Maximum deviation while alarm active f) Trending information while alarm active — operator interventions: operator intervention may affect processing batch. operator intervention typically logged with following information: a) Intervention type b) Operator ID 74 ANSI/ISA-S88.01-1995 Late entries Late entry data data entered after execution part control recipe procedure which it related, after production batch. typically data related off-line measurements analyses. Manage batch history includes logging such entries, including establishing link associated batch events (like sampling). following data may be associated with late entries: — Measured value(s) — Operator ID — Lab technician ID — Time entry — Time sample 6.4.2 Manipulating historical data following functions typical: — Data manipulation: altering (if legal) supplementing archived batch data. — Calculations: perform calculations batch data creating new batch data related to batch. — Data reduction: data reduction batch history information especially relevant with trend information. Loss data connection with data reduction should well defined related dynamics data, well requirements information based data. — Batch tracking information: establishing maintaining links between batch histories corresponding physical movements batches, ranging from use batch raw material another, splitting combining batch histories due splitting or combining batches. 6.4.3 Producing batch reports section export data — electronically paper — designated report. batch report is, general, made specific request. Such request must possible without knowledge equipment time production. case when — batch ID used entry key access data, piece equipment; — timing relative identified batch events (start batch, start operation, etc.); — entries identified generic, batch-related terms equipment-specific tags. Recipients batch reports Batch history data may retrieved request number reasons: — Production management: production overview summaries, consumption raw materials other resources, lot batch tracking information — Recipe management: recipe optimization information, comparison between recipe data actual values, analysis correlation across several batches, comparison trend information ANSI/ISA-S88.01-1995 75 — Process management: history current batches comparisons with old batches for operator display process control optimization — External systems: a) quality control: statistical process control, compliance with product specifications, GMP (Good Manufacturing Practice) documentation b) maintenance: alarms, equipment usage documentation c) financial: raw material consumption, yields, produced quantities, etc. d) customer support: product documentation — Internally within manage batch history: Process Management may include functions to perform queries mentioned above ability export print them request, at regular intervals, after each batch. Elements batch reports Some possible elements batch report include — report header: header contains information report type, batch batches displayed report, descriptive text, etc. — single elements: These data elements displayed somewhere paper/screen. — event lists: These chronological lists event-type entries with associated data. For example, might include list alarms list operator interventions. — merging entries event lists: Entries with different tags different types may be merged into same list. — selection entries into lists: Entries may selected according different criteria before entering lists. example, entries may include only high priority alarms. — trends: These displays show more values same time axis. a) single batch trend: These trends display data from batch portion of batch . They may display several values with individual time axis. display may be relative absolute time. b) multi-batch trend: These trends compare values from several batches trend display. They must with relative time-axis. Some variables may be normalized standard amount. c) event-marking trends: Events may introduced trend display "ticks" trends other indications. tick should refer specific event-type entry. — time-series: These displays time-series more entries table-like fashion. time-deadband, which how close time entries with different tags have to be order displayed same line, must specified time series displays. — interpolation: Rules interpolation data have established if data with different entry-times have displayed line if data used calculations. 76 ANSI/ISA-S88.01-1995 6.5 Process management Process Management collection control functions manages batches resources within process cell. Within control activity, control recipes created from master recipes, each batch defined entity, individual batches initiated supervised, resources within process cell managed resolve conflicts use process cell batch data collected. Process Management interfaces with Unit Supervision, Recipe Management, Production Planning Scheduling, Production Information Management (see Figure 22). Figure 22 — Process management At process cell level, there often multiple batches multiple units, each unit may be carrying out unit procedure different batch. progression procedure each batch utilization individual pieces equipment has coordinated based information derived from control recipe, scheduling information, status equipment other common resources. Recipe Management Production Planning Scheduling Batch Scheduling Information Batch Information Commands Unit Recipes, Status Information Commands, Batch Status Information Batch Process Cell Information Batch Progress Process cell Status Information Manage Process Cell Resources Unit Supervision Manage Batches Collect Batch Process Cell Information Production Information Management Master Recipe Batch Resource Information Process Cell Information ANSI/ISA-S88.01-1995 77 domain Process Management process cell. successful execution control recipe makes batch, Process Management finished with batch when control recipe procedure complete. batch has been produced does have final product. It may take several control recipes running same process cell different process cells and/or sites make finished product(s). When batch leaves process cell, it longer responsibility Process Management associated with process cell terms identification, batch tracking, etc. Process Management can discussed terms following three control functions (see Figure 22): — Manage batches — Manage process cell resources — Collect batch process cell information 6.5.1 Manage batches This control function which control recipe created from copy master recipe, batch initiated based scheduling information operator input, execution of batch supervised. following capability typically included control function: — Creating control recipe from master recipe, scheduling information, input received from operator. may happen with widely varying lead times, such at instant needed some situations well advance scheduled execution time others. control recipe may created initially its entirety, it may created incrementally information needed. — Assigning unique batch identification (batch ID) each batch associated control recipe. batch may identified named many different ways, least identification, referred here batch ID, must verified totally unique within process cell given time. batch ID may provided operator, scheduling information, from within Process Management, uniqueness typically verified before it associated with batch. — Verifying control recipe it created. Verifying consists ensuring control recipe complete executable selected set units. includes verifying that procedural elements available, formula information valid, that necessary resources can expected available when needed. — Sizing control recipe meet batch quantity needed based sizing rules master recipe quantity specified batch scheduling information. recipe may include range over which it may scaled. — Maintaining current control recipes within Process Management until batches are completed. — Assigning start conditions specified scheduling information and/or provided by operator. Some batch start conditions may used, either individually some combination, include following: a) Start batch soon unit becomes available b) Start based operator direction c) Start when specific units available 78 ANSI/ISA-S88.01-1995 d) Start based scheduled priority batch — Modifying part control recipe has been executed. may include ability modify procedure, such adding deleting unit procedures, operations, and/or phases, looping back repeat unit procedures, operations, and/or phases that have previously been executed. — Requesting releasing units other equipment, changing status indicate use, updating manage process cell resources control function status batch. — Monitoring controlling executing control recipe(s) including current status of batch, such what unit procedures have been executed, what unit procedure next. — Processing requests state mode changes procedures, unit procedures, operations, phases. — Allowing control recipe span multiple units same process cell, including distributing unit recipes Unit Supervision timely manner. — Allowing batch suspended, removed from processing equipment (packaged for temporary storage), therefore out control Process Management, later recalled complete batch processing. — Maintaining batch status information. control recipe, including modifications, should logged part batch history it executed least when batch leaves process cell. — Updating information batches collect batch process cell information control function. 6.5.2 Manage process cell resources This control function which process cell resources managed allocating reserving units other equipment, arbitrating multiple requests same equipment, providing mechanism controlling unallocated equipment. Process cell resources also include materials within process cell. Process cell resource management must know which materials process cell, location, disposition. assignment resources process cell unit level (resource allocation) needs be provided order Process Management able assign equipment equipment options from batch schedule. Some limited equipment reassignment generation new resource allocation process cell unit level may also needed operator. new resource allocation may necessary because such variables malfunction equipment or availability raw materials. Production Planning Scheduling may require notification of this new resource allocation allow assessment impact. following capabilities typically included control function: — Obtaining scheduling information from Production Planning Scheduling providing information manage batches control function — Allocating reserving equipment requested manage batches control function. Within process cell, batches may move from unit unit. each unit portion control recipe, corresponding unit procedure, executed. control what equipment allocate different batches, when transfers can take place may ANSI/ISA-S88.01-1995 79 require control process cell level. Some examples how allocation may done are a) according batch schedule designating each individual unit allocation; or b) according strategy defined process cell level combining equipment requirements control recipe availability capabilities equipment. — Arbitrating, required, multiple requests reservation allocation same equipment. rules arbitration may simple complex, depending application. Examples arbitration rule sets include following: a) Order request (FIFO) b) Timed requests (such reserving equipment) c) Priority batch d) Maximizing equipment utilization (such minimizing cleaning requirements, minimizing energy consumption, maximizing throughput) e) Operator judgment — Managing unallocated equipment within process cell — Receiving status information sent Unit Supervision and/or status information sent by Process Control related unallocated equipment within process cell — Updating information process cell resources collect batch process cell information control function — Updating Production Planning Scheduling with batch progress information, such a) batch ID; b) batch state change events; c) actual quantities raw materials, products, utilities; d) equipment assignments; e) projected actual allocation de-allocation times process cell resources. 6.5.3 Collect batch process cell information This control function which information collected about Process Management events, both batch equipment oriented, from manage batches manage process cell resources control functions. information made available Production Information Management. Examples types information collected include following: — Mode state changes — Incremental copies control recipes each portion finished — Time commands sent Unit Supervision Process Control — Time unit recipes sent Unit Supervision — Delays encountered due lack equipment availability 80 ANSI/ISA-S88.01-1995 — Time allocation, reservation release each process cell resource — Requests result requests equipment allocation reservation which required arbitration — Status changes unallocated equipment — Operator intervention 6.6 Unit supervision Unit Supervision control activity ties recipe equipment control via Process Control (see Figure 23). control activity interfaces with Process Management, Process Control, Production Information Management. There three main control functions within this control activity discussed section. They include acquiring executing procedural elements, managing unit resources, collecting batch unit information. Figure 23 — Unit supervision Process Management Batch Information Commands Status Information Commands Status Information Manage Unit Resources Process Control Acquire Execute Procedural Elements Collect Batch Unit Information Production Information Management Batch Resource Information Unit Information Unit Recipes, Commands Status Information Batch Unit Information ANSI/ISA-S88.01-1995 81 6.6.1 Acquire execute procedural elements Process Management supplies unit recipe executed within unit also supplies other batch information required manufacture batch. Unit Supervision has able determine from unit recipe procedural logic run, appropriate parameters, equipment entities utilized, other pertinent information, such name product, equipment restrictions, batch number. Acquire execute procedural elements includes execution unit procedures. If unit procedure part equipment control unit, control function associates recipe unit procedure, including parameters, with equipment unit procedure. Acquire execute procedural elements includes execution operations. If operation part equipment control unit, control function associates recipe operation, including parameters, with equipment operation. initiation parameterization of phases part execution operation. Acquire execute procedural elements includes initiation and/or execution phases. If phase part equipment control unit, control function associates recipe phase, including parameters, with equipment phase. If phase part equipment control equipment module, control function must initiate parameterize equipment phase. following capabilities typically included control function: — Determining which procedural elements executed — Verifying procedural elements exist — Executing unit procedures, operations, phases — Associating recipe procedural elements with equipment procedural elements — Initiating parameterizing equipment phases 6.6.2 Manage unit resources This control function includes management resources part unit, management resources might have been acquired have yet been released, initiation requests resources currently part unit, requests services from other units, providing services another unit. During execution recipe, it may necessary acquire shared-use and/or exclusive-use resources subsequently released. Although units cannot acquire other units, they can request services from provide services another unit long recipe has specified compatible procedural logic both units. phases operations units can communicate perform coordinated function. Unit-to-unit coordination may used enable functions such material transfers between units. following capabilities typically included control function: — Issuing requests to, reacting feedback from, interfacing with arbitration functions related equipment question — Ensuring appropriate propagation unit procedural element modes states — Enabling collection production information relevant batch from external equipment 82 ANSI/ISA-S88.01-1995 6.6.3 Collect batch unit information Collect Batch Unit Information control function makes information available to Production Information Management about Unit Supervision events, both batch equipment oriented. Data collection may conditional. is, certain data might always collected might be sampled different time interval, depending upon information received from another control function, such from parameters passed equipment phase. Examples types information collected include following: — Mode state changes — Timing commands sent Process Control — Timing execution unit recipe procedure events — Timing sequence allocation, reservation, release equipment entities acquired unit — Status changes unit equipment — Values derived during execution unit recipe 6.7 Process control This control activity encompasses procedural basic control, including sequential, regulatory, discrete control, addition gathering displaying data. control activity be distributed among several equipment entities, including units, equipment modules control modules. It interfaces with Production Information Management, Unit Supervision, Personnel Environmental Protection. Process Control can discussed terms three control functions: execute equipment phases, execute basic control, collect data (see Figure 24). ANSI/ISA-S88.01-1995 83 Figure 24 — Process control 6.7.1 Execute equipment phases This control function which equipment entities receive commands perform procedural control described equipment phase. control function initialized Acquire execute procedural element control function Unit Supervision (6.6.1). definition, equipment phase configured part equipment entity. However, parameter values may be necessary order execute equipment phase. Execute equipment phase control function interprets phase initialization command associates necessary parameters with equipment phase. Equipment phases may commanded parameterized before or during execution. Equipment entities capable performing control function equipment modules units. This control function does act directly physical equipment. It influences process only through basic control control module. Unit Supervision Execute Basic Control Personnel Environmental Protection Execute Equipment Phases Collect Data Production Information Management Commands Status Information Data Data Commands Status Information Data Commands Status Information Commands Status Information Commands Status Information 84 ANSI/ISA-S88.01-1995 This control function also includes supervision equipment phase modes states. This includes — propagation modes states from/to procedural element and/or equipment entity; — propagation modes states from unit equipment module executing equipment phase; — manual intervention into execution equipment phase. 6.7.2 Execute basic control Executing basic control control function causes changes equipment process states sending commands actuators other control modules. Commands basic control may come from execution equipment phase from another control function, such manual command from operator. Basic control uses input from sensors other control functions order execute its function. execution control function may also result process, equipment, other status information being provided high level control functions. Some other basic control functions may included exception handling, calculations, treatment operator-entered information, etc. However, control function does contain procedural control always configured part equipment entity. control function also includes association necessary parameters with appropriate basic control function. Equipment entities capable performing this control function control modules, equipment modules, units. This control function also includes supervision equipment entity modes states. This includes — propagation modes states from/to equipment entities and/or procedural elements; — manual intervention. Where equipment entity common resource, control function may also involved arbitration conflicting requests commands. 6.7.3 Collect Data Collect Data control function, data from sensors, derived values, events occur within domain Process Control collected stored batch history. Data collection may conditional. is, certain data might always collected might sampled different time interval, depending upon information received from another control function, such from parameters passed equipment phase. 6.8 Personnel environmental protection Personnel Environmental Protection control activity provides safety people environment. It shown Control Activity Model Figure 19 (see Section 6.1.1) below Process Control because other control activity should intervene between Personnel Environmental Protection, field hardware it designed operate with. Personnel Environmental Protection is, definition, separate from higher level control activities. It may map more than level equipment entity if level organization sophistication required provide adequate safety protection. ANSI/ISA-S88.01-1995 85 Personnel environmental protection included control activity model emphasize importance these types protection systems indicate point model appropriate insertion separate protection system type. complete discussion of personnel environmental protection, classification these types systems, segregation levels interlocks within these systems topic its own beyond scope of standard. More information topic can obtained from some standards guidelines under development (see References 1, 2, 3, 4, 5 Annex B). ANSI/ISA-S88.01-1995 87 Annex — (normative) Model philosophy number drawing formats have been used standard. Each these drawing formats discussed below. modeling formats discussed section provide non-rigorous method portraying information relationships. They intended recommend imply analysis methodology have figures supersede information described text. — Entity-Relationship (E-R) diagrams shown using format described Figures A.1 A.2. description relationship shown direction only. Figure A.3 example. — Entities shown rectangles drawings. — Activities functions shown rounded rectangles drawings. These drawings only show explosion control activity per diagram. Lines between activities between functions show information exchange. example Figure A.4. — States shown ellipses drawings. Lines between states identify commands that cause state changes. Figure A.5 example state transition diagram. — Physical drawings use ISA symbol standards, applicable. Figure A.6 example. — Nested drawings only used it desirable show relationship between two different types recipes. Figure A.7 example. 88 ANSI/ISA-S88.01-1995 Figure A.1 — Basic looped associations Entity-Relationship diagrams Basic Associations: Looped Associations: Any associations above may used loop. Here, occurrence of entity associated with more occurrences entities of same type. Enterprise B For each occurence A, there only occurrence B. For each occurence A, there zero occurrence B. B For each occurence A, there more occurrences B. B For each occurence A, there zero, one, or more occurrences B. B ANSI/ISA-S88.01-1995 89 Figure A.2 — Labeled associations Entity-Relationship diagrams Labeled Associations: label written next entities. case, it reads: consists B. case, it reads: references B. B consists of B references 90 ANSI/ISA-S88.01-1995 Figure A.3 — Process model (Entity-Relationship diagram) Procedure Unit Procedure Operation Phase consists ordered set of consists ordered set of consists ordered set of ANSI/ISA-S88.01-1995 91 Figure A.4 — Process control (control activity with breakdown into control functions) Unit Supervision Execute Basic Control Personnel Environmental Protection Execute Phases Collect Data Production Information Management Data Data Commands Status Information Data Commands Status Information Commands Status Information Commands Status Information Commands Status Information 92 ANSI/ISA-S88.01-1995 Figure A.5 — State transition diagram Figure A.6 — Single-path structure (physical drawing) Restarting Running Abort Stop Aborting Reset Reset Start Pause Hold Resume Restart Reset Stopping Idle (Initial State) Holding Pausing Paused Complete Aborted Stopped Held Final States Quiescent States Transient States UNIT 1 UNIT 2 Input Materials Storage Finished Materials Storage ANSI/ISA-S88.01-1995 93 Figure A.7 — Site recipe procedure master recipe procedure relationship (nesting model) Site Recipe Procedure Process Stage Process Operation Process Action Master Recipe Recipe Procedure Recipe Unit Procedure Recipe Operation Recipe Phase ANSI/ISA-S88.01-1995 95 Annex B — (informative) Bibliography 1. ISA-dS84.01: Applications Safety Instrumented Systems Process Industries, Instrument Society America. 2. IEC SC65A/WG10, 65A (Secretariat) 122: Functional safety: safety-related systems. Part 1: General requirements, International Electrotechnical Commission. 3. IEC SC65A/WG9, 65A (Secretariat) 122: Functional safety: safety-related systems. Part 2: Requirements Electrical/Electronic/Programmable electronic systems, International Electrotechnical Commission. 4. IEC SC65A/WG9, 65A (Secretariat) 122: Functional safety: safety-related systems. Part 3: Software requirements, International Electrotechnical Commission. 5. Guidelines Safe Automation Chemical Processes, Center Chemical Process Safety, American Institute Chemical Engineers, New York 1993. 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