MODELLING, ANALYSIS AND DESIGN OF COMPUTER INTEGRATED MANUEACTUR1NG SYSTEMS Volume I of II ABDULRAHMAN MUSLLABAB ABDULLAH AL-AILMARJ October-1998 A thesis submitted for the DEGREE OP DOCTOR OF.PHILOSOPHY MECHANICAL ENGINEERING DEPARTMENT, THE UNIVERSITY OF SHEFFIELD 3n ti]S 5íamc of Allai]. ¿Hoot (gractouo. iHHoßt ¿Merciful. ACKNOWLEDGEMENTS I would like to express my appreciation and thanks to my supervisor Professor Keith Ridgway for devoting freely of his time to read, discuss, and guide this research, and for his assistance in selecting the research topic, obtaining special reference materials, and contacting industrial collaborations. His advice has been much appreciated and I am very grateful. I would like to thank Mr Bruce Lake at Brook Hansen Motors who has patiently answered my questions during the case study. Finally, I would like to thank my family for their constant understanding, support and patience. l To my parents, my wife and my son. ABSTRACT In the present climate of global competition, manufacturing organisations consider and seek strategies, means and tools to assist them to stay competitive. Computer Integrated Manufacturing (CIM) offers a number of potential opportunities for improving manufacturing systems. However, a number of researchers have reported the difficulties which arise during the analysis, design and implementation of CIM due to a lack of effective modelling methodologies and techniques and the complexity of the systems. The work reported in this thesis is related to the development of an integrated modelling method to support the analysis and design of advanced manufacturing systems. A survey of various modelling methods and techniques is carried out. The methods SSADM, IDEFO, IDEF1X, IDEF3, IDEF4, OOM, SADT, GRAI, PN, 10A MERISE, GIM and SIMULATION are reviewed. The majorities of these contain graphical components and therefore, fulfil basic modelling requirements. In addition, these methods represent a comprehensive sample of manufacturing systems modelling methods. A manufacturing system comprises different sub-systems including physical, information and decisions sub-systems. These sub-systems can be modelled using a combination of the methods described i.e. GRAI for decision systems, IDEFO for physical systems, simulation for dynamic aspects, etc. A novel framework for comparing the modelling methods selected is developed using a number of factors derived from CIM and modelling requirements. The study discovered that no single modelling method or technique could model all the different aspects of a manufacturing system or achieve integration between system domains at both static and dynamic levels. As a result, it was concluded that there was a need for an integrated modelling method for the analysis and design of complex manufacturing systems. To overcome these problems, a novel integrated modelling method called GI-SIM has been developed. The method is composed of four modelling components GRAI grid, IDEFO, IDEF1X and SIMAN/ARENA. GI-SIM integrates these four tools to form a complete method, which combines the advantages of existing modelling methods and eliminates their shortcomings. 111 The method developed is evaluated using a case study carried out in a UK company manufacturing electric motors. It is also tested for the design and specification of CIM system components (CAD, CAPP, CAM, etc.). The case studies demonstrate that GI- SIM achieves two important types of modelling integration; the first is a vertical integration between different levels of abstraction (conceptual, structural and dynamic) and the second is a horizontal integration between five modelling domains (decision, functional, information, physical and dynamic). In addition, the method is easy to learn and use, and sufficiently flexible to model any system function according to its related objectives. The findings of this research and recommendation for future research are presented in the final chapter. tv RESEARCH PAPERS The following papers have been published as a direct result of this research: International Journals: Al-Ahmari A.M.A. and Ridgway K. (1998) “An Integrated Modelling Method to Support Manufacturing Systems Analysis and Design” Accepted for publication in Computers in Industry. Refereed International Conferences: Al-Ahmari AM.A. and Ridgway K. (1997) “Computerised Methodologies for Modelling Computer Integrated Manufacturing Systems” Proceedings of the 32nd International MATADOR Conference, Manchester, pp 111-116. Al-Ahmari A.M.A. and Ridgway K. (1998) “Modelling of Manufacturing Systems for SMEs” Proceedings of the 1st International SMESME Conference, Sheffield, pp 29-33. Al-Ahmari A.M.A. and Ridgway K. (1998) “The Development of an Integrated Modelling Method for Manufacturing Systems Analysis and Design” 3rd International Conference - Managing Innovative Manufacturing (MIM ’98), University of Nottingham. Conferences and seminars: Al-Ahmari A.M.A. (1998)“GI-SIM Modelling Method” 5th International AUGRAI Workshop, University of Strathclyde, August 24th-25th. TABLE OF CONTENTS Volume I ACKNOWLEDGEMENTS............................................................................................I ABSTRACT....................................................................................................................Ill RESEARCH PAPERS....................................................................................................V TABLE OF CONTENTS................................................................................................VI LIST OF TABLES.......................................................................................................... XI LIST OF FIGURES................................................................... XII CHAPTER-1 .................................................................................................................. 1 INTRODUCTION......................................................................................................1 1.1. Background Of The Research........................................................................ 1 1.2. The Need For Modelling Methods................................................................. 2 1.3. Aims And Objectives Of The Research..........................................................3 1.4. Thesis Structure.............................................................................................. 5 CHAPTER-2.................................................................................................................. 9 MANUFACTURING SYSTEMS AND CIM DEFINITION....................................9 2.1. Introduction....................................................................................................... 9 2.2. System Definition..............................................................................................9 2.3. System Classifications.....................................................................................10 2.4. Manufacturing Systems...................................................................................10 2.5. Types of Manufacturing Systems................................................................... 13 2.5.1 Job Shop Manufacturing System...............................................................15 2.5.2 Project Shop Manufacturing System........................................................ 16 2.5.3 Cellular Manufacturing Systems...............................................................16 2.5.5. Flow line Manufacturing System...........................................................17 2.6. Manufacturing Systems Review....................................................................17 2.7. Manufacturing Strategy...................................................................................19 2.8. CIM Strategy................................................................................................... 21 2.9. CIM Definition................................................................................................22 2.9.1 A Discussion on CIM Definitions..............................................................24 2.9.2 Reasons for the Different Definitions of CIM ...........................................25 2.10. Why CIM?................................................................................................... 28 2.11. CIM Components........................................................................................30 2.12. Component Integration................................................................................33 2.13. Conclusion....................................................................................................35 CHAPTER-3..................................................................................................................37 CIM: LEARING FROM PRACTICE........................................................................37 3.1. Introduction......................................................................................................37 3.2. CIM Applications............................................................................................ 37 3.3. Obstacles to CIM Implementation.................................................................. 47 3.3.1 CIM Complexity......................................................................................47 vi 3.3.2 The Integration Barrier.............................................................................. 48 3.3.3 Lack of Understanding of CIM and its Potential.......................................48