Proceedings of the third International Workshop of the IFIP WG5.7

Contents of the papers presented at the international workshop deal with the wide variety of new and computer-based techniques for production planning and control that has become available to the scientific and industrial world in the past few years: formal modeling techniques, artificial neural networks, autonomous agent theory, genetic algorithms, chaos theory, fuzzy logic, simulated annealing, tabu search, simulation and so on. The approach, while being scientifically rigorous, is focused on the applicability to industrial environment

Modelling, analysis and design of computer integrated manufacturing systems.

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. 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 GISIM 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

Process assessment for the extended enterprise during early product development using novel computational techniques

Manufacturing practices have evolved over the last quarter of a century in the light of changes to manufacturing technology and demand. To sustain this growth companies are increasingly focused on better design and quicker time to market, to stay one step ahead of the competition. Expanding technology capabilities have included microcomputers and telecommunications. In particular the Internet has allowed businesses to trade with an extended customer base, resulting in a greater demand and perpetuating the cycle. To mirror this statement, businesses are looking increasingly far and wide for suitable suppliers. This work identifies a need in the market for an Internet based supplier selection function, during early product development. The development of this work differs significantly from other process selection methods by the use of the Internet to link companies. It has advantages for product development relating to the scope of the opportunities, diversity of possible manufacturing operations and rapid assessment of processes. In particular the system can be broken down into two main functions. Process Selection (PS) and Factory Selection (FS). The PS method presented enables many processes to be modelled, in multiple organisations for a single product. The Internet is used to gain access to supplier facilities by adopting the same principles as on-line banking, or shopping, for data input and access. The results of these assessments are retained by the system for later analysis. The FS method utilises this data to model and compare supplier attributes, allowing the user to manipulate the data to fit their requirements. Testing of the system has proved encouraging for many operations, including Injection Moulding and CNC Machining. It can be concluded that the identification of manufacturing operations outside the remit of companies' normal scope will create further opportunities for supplier integration