Table Of ContentShop Floor Control Systems
The material in this book expresses only the views of its authors,
and is in no way a statement of Digital Equipment Corporation.
Shop Floor Control Systems
From design to implementation
A. Bauer, R. Bowden, J. Browne, J. Duggan and G. Lyons
a
1 111
Springer-Science+Business Media, B. V.
First edition 1991
@ 1994 Springer Science+Business Media Dordrecht
Originally published by Chapman & Hall in 1991, 1994
ISBN 978-0-412-58150-2 ISBN 978-94-011-1296-3 (eBook)
DOI 10.1007/978-94-011-1296-3
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CONTENTS
Figures viii
About the authors XI
Acknowledgements XIII
Preface xv
Foreword xix
PART ONE: BACKGROUND TO SHOP FLOOR
CONTROL SYSTEMS
Overview 1
1 A background to shop floor control systems 3
1.1 Introduction 3
1.2 The Just in Time approach to production management 5
1.3 An overview of requirements planning (MRP and MRP II) 12
1.4 MRP fOPT versus JIT 24
1.5 Guidelines for the development and installation of
production planning and control systems 25
1.6 An architecture for production planning and control 26
1.7 Conclusions 32
PART TWO: A FUNCTIONAL ARCHITECTURE FOR
SHOP FLOOR CONTROL SYSTEMS
Overview 33
2 An architecture for shop floor control systems 35
2.1 Introduction 35
2.2 Production Activity Control 36
2.3 Factory coordination 46
2.4 Conclusions 62
v
VI Contents
3 A structured functional model for shop floor control 64
3.1 Introduction 64
3.2 Structured Analysis and Design Technique 65
3.3 Overview of SADT™ model for FC and PAC 70
3.4 AO: Coordinate the factory 74
3.5 AI: Design the production environment 75
3.6 A2: Coordinate the product flow 83
3.7 Conclusions 94
PART mREE: AN INFORMATION TECHNOLOGY
ARCHITECTURE FOR SHOP FLOOR CONTROL
Overview 95
4 An information technology architecture for shop floor control 97
4.1 Introduction 97
4.2 The concepts of a layered architecture 98
4.3 The entities and core services of the reference architecture 101
4.4 A descriptive summary of Petri nets 108
4.5 A sample protocol of the reference architecture 113
4.6 Conclusions 119
5 Implementation technologies for shop floor control systems 120
5.1 Introduction 120
5.2 An overview of information technology 121
5.3 Communication systems 123
5.4 Data management systems 129
5.5 Processing systems 137
5.6 User interfaces 141
5.7 The object oriented approach 144
5.8 Conclusions 148
PART FOUR: STATE-OF-THE-ART REVIEW
Overview 149
6 A review of scheduling strategies 151
6.1 Introduction 151
6.2 Traditional scheduling approaches 152
6.3 Modern scheduling approaches 164
6.4 Conclusions 178
7 A review of production environment design strategies 179
7.1 Introduction 179
7.2 Product based manufacturing 180
7.3 Process planning 196
7.4 Manufacturing system analysis 203
7.5 Conclusions 207
Contents Vll
PART FIVE: THE IMPLEMENTATION OF
SHOP FLOOR CONTROL SYSTEMS
Overview 209
8 An approach to the implementation of factory
coordination and production activity control systems 211
8.1 Introduction 211
8.2 Sociotechnical design 212
8.3 The contribution of sociotechnical design to the
implementation of PMS 226
8.4 The environment for Factory Coordination and
Production Activity Control 231
8.5 Conclusions 242
9 A design tool for shop floor control systems 244
9.1 Introduction 244
9.2 The application generator 245
9.3 The manufacturing database 248
9.4 The rulesbase 252
9.5 The PAC simulation model 255
9.6 Using the AG in the electronics industry 269
9.7 Conclusions 274
PART SIX: AN IMPLEMENTATION OF
A PAC SYSTEM
Overview 277
10 The environment of the case study 279
10.1 Introduction 279
10.2 The business environment 280
10.3 The production management system environment 283
10.4 The technical and social sub-systems 288
10.5 The information technology environment 295
10.6 Conclusions 297
11 Implementation of a PAC system 298
11.1 Introduction 298
11.2 Description of the pilot implementation 299
11.3 Architectural mapping and implementation software 303
11.4 Lessons and guidelines 308
11.5 Conclusions 312
12 References and further reading 314
12.1 References 314
12.2 Further reading 334
Index 336
FIGURES
The structure of the book. xvii
Figure 1.1 Breakdown of the lead time in a batch production system. 4
Figure 1.2 Components of production smoothing. 9
Figure 1.3 Basic structure of an MRP system. 14
Figure 1.4 Manufacturing resource planning. 18
Figure 1.5 NBS hierarchy. 28
Figure 1.6 Manufacturing controls systems hierarchy. 29
Figure 2.1 Production Activity Control. 37
Figure 2.2 The link between production environment design
and control. 47
Figure 2.3 Process based layout vs. product based layout. 49
Figure 2.4 The production environment design task within
factory coordination. 50
Figure 2.5 Data exchange between the control task of factory
coordination and a number of PAC systems. 55
Figure 2.6 An overall picture of the factory coordination architecture. 63
Figure 3.1 SADTTM model showing structured decomposition
(Ross, 1985). 66
Figure 3.2 Parent and child relationship (Ross, 1985). 67
Figure 3.3 Input, output, control and mechanism of an
SADT™ box (Ross, 1985). 69
Figure 3.4 A-I: Context diagram for coordinate factory. 71
Figure 3.5 A-O: Coordinate factory. 72
Figure 3.6 AO: Coordinate the factory. 75
Figure 3.7 AI: Design the production environment. 76
Figure 3.8 All: Develop process plan. 78
Figure 3.9 A12: Maintain product based layout. 79
Figure 3.10 A13: Analyse manufacturing system. 81
Vlll
Figures ix
Figure 3.11 A2: Coordinate product flow. 83
Figure 3.12 A21: Schedule factory. 85
Figure 3.13 A22: Dispatch factory. 86
Figure 3.14 A24: Control cells. 88
Figure 3.15 A241: Schedule cell. 89
Figure 3.16 A242: Dispatch cell. 90
Figure 3.17 A245: Monitor cell. 91
Figure 3.18 A25: Monitor factory. 93
Figure 4.1 Architectural mapping from functional to layered. 100
Figure 4.2 Layered architecture for FC and PAC. 101
Figure 4.3 Petri net graph based on Table 4.1. 110
Figure 4.4 A marked Petri net. 111
Figure 4.5 Petri net after firing transition 1. 112
Figure 4.6 Timing of a Petri net. 112
Figure 4.7 Initial Petri net model for dispatcher and
producer interaction. 116
Figure 4.8 Petri net after dispatcher commands the producer to start. 117
Figure 4.9 Petri net after the producer commences. 118
Figure 5.1 General computing model. 123
Figure 5.2 OSI reference model. 125
Figure 5.3 EDI concept. 127
Figure 5.4 Implementation scenario for communication. 129
Figure 5.5 Hierarchical data model. 130
Figure 5.6 Network data model. 131
Figure 5.7 Implementation scenario for data management. 137
Figure 5.8 Implementation scenario for processing. 140
Figure 5.9 Implementation scenario for the user interface. 143
Figure 5.10 Traditional design of software systems. 144
Figure 5.11 Object oriented approach. 145
Figure 5.12 Concept of object oriented technology. 146
Figure 6.1 Possible sequences of 4 jobs A, B, C and D
(Cunningham and Brownie, 1986). 156
Figure 7.1 An example of a monocode coding system. 185
Figure 7.2 Two components of similar shape and size, but different
manufacturing characteristics. 186
Figure 7.3 The formation of block diagonals in a matrix. 191
Figure 7.4 An example of a composite product. 194
Figure 7.5 Parallel approach of design and manufacturing. 203
Figure 7.6 Breakdown of the production lead time. 204
Figure 8.1 Inclusion of feedback in a system. 215
Figure 8.2 The transactional and contextual environments
(Pava, 1983). 216
x Figures
Figure 8.3 An approach to sociotechnical design. 224
Figure 8.4 View of an organization within its environment
(Brownie et ai., 1988). 235
Figure 8.5 The different flows in a technical sub-system. 237
Figure 8.6 Manufacturing controls systems hierarchy. 238
Figure 8.7 A two-stage scheduling procedure. 240
Figure 8.8 A sample Gantt chart. 241
Figure 8.9 The two type of inputs used in the interactive
scheduling task. 242
Figure 9.1 The PAC life cycle model. 245
Figure 9.2 Combinative operation. 251
Figure 9.3 Sequential operation. 252
Figure 9.4 Inspection operation. 252
Figure 9.5 Disjunctive operation. 253
Figure 9.6 Sample output for the interactive scheduler. 257
Figure 9.7 Petri net model of a completed producer task. 261
Figure 9.8 The command from the dispatcher reaches the Petri net. 263
Figure 9.9 Petri net fires transition 1. 264
Figure 9.10 Petri net fires transition 2. 265
Figure 9.11 Test area layout for the application generator. 270
Figure 9.12 Sample output from the rulesbase. 274
Figure 9.13 Monitor screen during the simulation run. 274
Figure 10.1 Integrated manufacturing business model. 283
Figure 10.2 The planning cycle at the Digital Equipment Corporation's
plant in Clonmel. 287
Figure 10.3 An ideal layout under continuous flow manufacturing. 291
Figure 10.4 The actual layout of the PCB assembly area and
unit assembly cells. 292
Figure 10.5 The four workcells within the common PCB assembly cell. 293
Figure 11.1 The hierarchy of PIM systems in Clonmel. 301
Figure 11.2 PAC in the test environment. 302
Figure 11.3 PAC implementation model in the Clonmel environment. 303
Figure 11.4 Implementation area for pilot PAC system. 305
Figure 11.5 Final PAC implementation. 306
Figure 11.6 The PAC implementation software. 307
Figure 11.7 The PAC scheduler. 311
Figure 11.8 The workcell monitor. 312
