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The exchange of information in the industrial environment is essential in order to achieve complete integration and control of manufacturing processes. At present the majority of devices present in the shop floor environment are still used as stand alone machines. They do not take advantage of the possibilities offered by a communication link to improve the manufacturing process. The subject of this research has been centered on the development of a simple, flexible and inexpensive support system for communication and control of manufacturing processes. As a result, a system with these features has been proposed and implemented on a simulated workcell. The area footwear manufacturing was chosen for modelling the workcell. The components of the manufacturing support system were developed using an object oriented approach which allowed modularity and software reuse. In order to achieve communication between the components, a communication protocol was developed following the process defined in the rapid protocol implementation framework. Ethernet was selected for implementing the lower levels of the protocol. Java, a new object oriented programming language used for the implementation of the system, showed that it could became a promising language for the implementation of manufacturing applications. In particular the platform independence feature of the language allows the immediate porting of applications to systems with different features. The manufacturing cell simulation had shown that the times associated with the manufacturing support system operations are compatible for its use in applications where the response times are in the order of one second.

This thesis describes a successful attempt to automate a manual process in footwear industry. The process is called skiving of leather components and it is one of the early processes necessary for the assembly of shoe uppers. Skiving is the localised thinning of leather components, mainly at some of their edge regions. The purpose of skiving is to produce quality decorative edges or more importantly to enable attaching and joining components without forming thick, discomforting and weak joints. Although other processes in footwear manufacturing have been subject to partial or full automation, skiving has been performed for decades now with a standard mechanism that requires 3-dimensional manipulation of the components by a human operator. This research work was directed towards two main aims. One was to establish a novel method on the basis of which skiving may be performed without the need of human assistance. The developed method is called dynamic matrix skiving and it is capable of performing skiving on leather components by generating and actuating skive patterns as sets of finite elements of skived area to a given resolution. Following derivation and study of the method for skiving, the second phase was aimed at implementing a fully automatic skiving system. The main requirement from the system was to be an intelligent, component oriented, flow through, processing device. This required the capability to receive input components at any orientation and position along its transport mechanism, to recognise them as to their identity and relative position, and to perform skiving upon them without moving them or disturb their continuous flow throughout the entire operation. Individual chapters in this thesis describe the study and experimentation with regards to dynamic matrix skiving, and all logical steps taken to identify the necessary elements and implement their integration to produce the automated skiving system. The concluding part of this work includes presentation of the results obtained from the automated system, and it identifies the areas where further research and development is needed in order to improve the quality of its output.

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The design of a manufacturing system is normally performed in two distinct stages, i.e. steady state design and dynamic state design. Within each system design stage a variety of decisions need to be made of which essential ones are the determination of the product range to be manufactured, the layout of equipment on the shopfloor, allocation of work tasks to workstations, planning of aggregate capacity requirements and determining the lot sizes to be processed. This research work has examined the individual problem areas listed above in order to identify the efficiency of current solution techniques and to determine the problems experienced with their use. It has been identified that for each design problem. although there are an assortment of solution techniques available, the majority of these techniques are unable to generate optimal or near optimal solutions to problems of a practical size. In addition, a variety of limitations have been identified that restrict the use of existing techniques. For example, existing methods are limited with respect to the external conditions over which they are applicable and/or cannot enable qualitative or subjective judgements of experienced personnel to influence solution outcomes. An investigation of optimization techniques has been carried out which indicated that genetic algorithms offer great potential in solving the variety of problem areas involved in manufacturing systems design. This research has, therefore, concentrated on testing the use of genetic algorithms to make individual manufacturing design decisions. In particular, the ability of genetic algorithms to generate better solutions than existing techniques has been examined and their ability to overcome the range of limitations that exist with current solution techniques. IIFor each problem area, a typical solution has been coded in terms of a genetic algorithm structure, a suitable objective function constructed and experiments performed to identify the most suitable operators and operator parameter values to use. The best solution generated using these parameters has then been compared with the solution derived using a traditional solution technique. In addition, from the range of experiments undertaken the underlying relationships have been identified between problem characteristics and optimality of operator types and parameter values. The results of the research have identified that genetic algorithms could provide an improved solution technique for all manufacturing design decision areas investigated. In most areas genetic algorithms identified lower cost solutions and overcame many of the limitations of existing techniques.

The flexl.bility to change product and processes quickly and economically represents a significant competitive advantage to manufacturing organisations. The rapid rise in global sourcing, has resulted in manufacturers having to offer greater levels of customisation, thus a wider product range is essential to an organisation's competitiveness. The rate at which new products are introduced to the market has also increased, with greatly reduced development times being essential to a new product's market success. Hence there is a strong need to have a flexible manufacturing system such that new products may be introduced rapidly. These drivers have made the need for flexibility within manufacturing systems of great importance. However, there are many types of flexibility and to ensure that organisations correctly target these types of flexibility there is a need to measure fleXlbility, because, measuring fleXlDility allows manufacturers to identify systems which will improve their performance. This research, therefore, has focused on the development measures for two types of flexibility ie. mix fleXlDility and product flexibility. These represent the ability to change between the manufacture of current products i. e. mix flexibility and the ability to introduce new products i.e. product fleXlDility. In order to develop effective measures for these types of fleXlbility a conceptual model has been developed, which represents the current and potential future product range of manufacturing systems. The methodology developed for measuring mix and product flexibility has been successfully applied in two companies. These companies represent diverse manufacturing environments. One operates in high volume chemical manufacture and the other in low to medium volume furniture manufacture. Through applying this methodology in these two companies it has been demonstrated that the methodology is generic and can be used in a wide range of companIes.