The work reported in this thesis is related to the development of a generic model for a 'make-to-stock’ manufacturing organisation. This research is based upon the hypothesis that every type of manufacturing company should have a generic model. The objectives of the model are first, to help SNIEs (Small and Medium sized Enterprises) who cannot afford external help and second, to fulfil the need for modelling that arose from a review of modelling literature. These were the basic driving forces in carrying out this research and from which the objectives are derived. A survey of various system design and analysis methods was carried out. Initially SSADM, SADT, IDEFO, NMRISE, STRIM and GRAI were selected for the study. The reason for the selection of these methods was that each contained graphical tools and fulfilled the requirements for modelling. Further investigation showed GRAI and IDEFO to be the most suitable methods for modelling manufacturing systems and these were selected for further investigation. A direct comparison of the GRAI and IDEFO methods was carried out using a case study. The results of this indicated that the GRAI method was the most suitable for the analysis and design of manufacturing systems and demonstrated advantages over the IDEFO method. For this reason the GRAI method was selected and applied to case study 'make-to-stock! manufacturing organisations. The case studies demonstrated that several similar characteristics existed in 'make-to-stock’ manufacturing organisations, supporting the hypothesis of the research. The case studies also indicated that the application methodology had some significant drawbacks. On the basis of this investigation, a detailed methodology to apply the GRAI method was formulated and validated using a further detailed case study. After the methodology had been validated, it was used to develop a generic model for a 'make-to-stock' manufacturing organisation. The model developed presents the activities carried out at the strategic, tactical and operational levels of the management hierarchy. Details of typical decision horizon and review periods are also included in the model. The thesis presents the first detailed methodology for applying the GRAI method and first application to develop a generic model. It also presents the first detailed comparison between the IDEFO and GRAI methods. The findings of this research and recommendations for future work are presented in the final chapter.

The need is expressed for mathematical models which describe the cutting tool-workpiece interaction and for accurate on-line monitoring of tool-state. These are essential requirements for the achievement of unmanned and computerized machining processes. Techniques are used to design the experiments which substantially reduce the number of tests while providing all the essential information for statistical analysis and for the development of mathematical models. The testing conditions are chosen to reasonably conform with the practical requirements. Multi-coated carbide tool inserts [Sandvik GC435] are used to cut an alloy steel [EN 19] under normal cutting conditions and for a wide range of operating parameters. An accurate and sensitive three-component dynamometer was designed, manufactured and used to measure the tool forces through a BBC microcomputer. Continuous records of the tool vibration have been collected in two different co-ordinate directions simultaneously together with measurements of tool wear and cutting forces. Linear and non-linear regression techniques are used to develop mathematical models for the experimentally measured responses: cutting forces, tool vibration, and tool wear. Special attention is devoted to the identification of the most appropriate models. Each model being capable of representing the tool state throughout its working lifetime. Tool life wear-based models are developed to relate the expected tool lifetime to the operating parameters: speed, feed, and depth of cut. A robust regression analysis technique, used in conjunction with iteratively re-weighting least-squares, has been found to improve the accuracy of the models, and to stabilize its computed residuals through the elimination of the effect of influential observations having high experimental error. Response surface methodology RSM has been used to signify the non-linear nature of tool life response. The force variation has been shown to correlate strongly with the wear progress so that it can be used for accurate in-process determination of tool wear and for monitoring tool state. It has been shown that the variation in the ratio between force components correlates with wear and is independent of the effect of other machining parameters; this enables the approach to be used for a wider range of materials and more extensive operational domain. Study of the power spectral analysis of the tool vibration indicates that among the tool's vibration modes, the first fundamental natural frequency of vibration in the feed direction exhibits a consistent correlation with wear-progress. The Vibration amplitude decreases with the increase of the wear level until it reaches a limit after which it tends to reverse its characteristic. The time at which the characteristic changes is found to closely correspond with the practical end of the tool lifetime. Based on this fact, an in-process approach is investigated to determine the tool life on-line. Also, a model has been developed for tool wear estimation based on a combination of vibration and force; and, very good agreement has been obtained with the experimental data. The validity of the models; their feasibility; and, their industrial significance are confirmed for adaptive control AC systems, and for machinability data base systems MDBS.

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The need for automated fault detection methods has increased in line with the complexity of processing plant technology and their control systems. Fast and accurate fault detection and isolation (FDI) is essential if a controller is to be effective in a supervisory role. This thesis is concerned with developing an FDI system based upon artificial neural network techniques. The artificial neural network (ANN) is a mechanism based upon the concepts of information processing within the brain, and consequently has the ability to self adjust, or learn about a given problem domain. It can thus be utilised in currently favoured model-based FDI systems with the advantage that it can learn process dynamics by being presented examples of process input-output pairs without the need for traditional mathematically complex models. Similarly, ANNs can be taught to classify characteristics in the residual (or plant-model difference) signal without the necessity of constructing the types of filter used in more classical solutions. Initially, a class of feedforward neural network called the multilayer perceptron (MLP) is used to model mathematically simulated linear and nonlinear plants in order to demonstrate their abilities in this field, as well as investigating the consequence of parameter variation on model effectiveness and how the model can be utilised in a model-based FDI system. A principle aim of this research is to demonstrate the ability of the system to work online and in real-time on genuine industrial processes, and the plant nominated as a test bed - the Unilever Automated Freezer (UAF) - is introduced. The UAF, being a time-varying system, requires a novel system identification approach which has resulted in a number of cascaded MLPs to model the various stages in the phased startup of the process. In order to reduce model mismatch to a minimum, it was necessary to develop an effective switching mechanism between one MLP in the cascade and the next. Attempts using a rule-based switching mechanism, a simple MLP switch and an error based switching mechanism were made, before a solution incorporating a genetic algorithm and an MLP network was developed which had the capability of learning the optimum switching points. After the successful development of the model, a series of MLPs were trained to recognise the characteristics of a number of faults within the residual signals. Problems involving false alarms between certain faults were reduced by the introduction of templates - or information pertaining to when a particular fault was most evident in the residuals. The final solution consisting of an MLP Cascade model and fault isolation MLPs is essentially generic for this class of time-varying system, and the results achieved on the UAF were far superior to those of the currently used FDI system without the need for any extra sensory information. The MLP Cascade and associated switching device together with the development of an online real-time FDI system for a time-varying piece of industrial machinery, are deemed to be original contributions to knowledge.

The continuing failure of many CAPM implementations in the UK, despite the availability of a large and growing supply of software, gave rise to concern within the academic and user community and highlighted a need for a concerted research effort into the causes of failure. The Science and Engineering Research Council responded to this need by sponsoring a major research initiative into CAPM through its ACME (Application of Computers to Manufacturing Engineering) Directorate. The findings reported in this thesis result from the work carried out for ACME by the author as part of the joint Polytechnic South West/Sheffield Business School research programme under the direction of professors D R Hughes, I S Smith and D R Tranfield. The extent of the work included surveying a large number of manufacturing firms, interviewing suppliers of CAPM systems and services and analysing the data collected from these activities. This resulted in the identification of a number of causes of CAPM failure. A major component of the work then concerned developing an appropriate CAPM design and implementation methodology to address the issues and concerns identified as significant. A clear distinction is made in the thesis between the work carried out by the author as part of the ACME team and the author's own work. The results from the joint effort of the research team are explained together with the author's unique contribution. The concepts of operational performance envelopes and contextually bound computing and information systems infrastructures provide the theoretical foundation to the author's approach. These concepts are utilised within an approach developed by the author which offers a wider ranging approach than is currently available. Existing approaches focus on the development of single point solutions and aim to address particular and current problems only. Such solutions are inappropriate where requirements are subject to rapid and frequent change, as in the manufacturing sector. In contrast the author's approach focuses on the development of a computing and information systems capability with the necessary flexibility to accommodate changing requirements and priorities. In this way a more resilient solution is obtainable.