23 resultados para Analog electronic systems -- Design

em Aston University Research Archive


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Research on production systems design has in recent years tended to concentrate on ‘software’ factors such as organisational aspects, work design, and the planning of the production operations. In contrast, relatively little attention has been paid to maximising the contributions made by fixed assets, particularly machines and equipment. However, as the cost of unproductive machine time has increased, reliability, particularly of machine tools, has become ever more important. Reliability theory and research has traditionally been based in the main on electrical and electronic equipment whereas mechanical devices, especially machine tools, have not received sufficiently objective treatment. A recently completed research project has considered the reliability of machine tools by taking sample surveys of purchasers, maintainers and manufacturers. Breakdown data were also collected from a number of engineering companies and analysed using both manual and computer techniques. Results obtained have provided an indication of those factors most likely to influence reliability and which in turn could lead to improved design and selection of machine tool systems. Statistical analysis of long-term field data has revealed patterns of trends of failure which could help in the design of more meaningful maintenance schemes.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This system is concerned with the design and implementation of a community health information system which fulfils some of the local needs of fourteen nursing and para-medical professions in a district health authority, whilst satisfying the statutory requirements of the NHS Korner steering group for those professions. A national survey of community health computer applications, documented in the form of an applications register, shows the need for such a system. A series of general requirements for an informations systems design methodology are identified, together with specific requirements for this problem situation. A number of existing methodologies are reviewed, but none of these were appropriate for this application. Some existing approaches, tools and techniques are used to define a more suitable methodology. It is unreasonable to rely on one single general methodology for all types of application development. There is a need for pragmatism, adaptation and flexibility. In this research, participation in the development stages by those who will eventually use the system was thought desirable. This was achieved by forming a representative design group. Results would seem to show a highly favourable response from users to this participation which contributed to the overall success of the system implemented. A prototype was developed for the chiropody and school nursing staff groups of Darlington health authority, and evaluations show that a significant number of the problems and objectives of those groups have been successfully addressed; the value of community health information has been increased; and information has been successfully fed back to staff and better utilised.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Using a hydraulic equipment manufacturing plant as the case study, this work explores the problems of systems integration in manufacturing systems design, stressing the behavioural aspects of motivation and participation, and the constraints involved in the proper consideration of the human sub-system. The need for a simple manageable modular organisation structure is illustrated, where it is shown, by reference to systems theory, how a business can be split into semi-autonomous operating units. The theme is the development of a manufacturing system based on an analysis of the business, its market, product, technology and constraints, coupled with a critical survey of modern management literature to develop an integrated systems design to suit a specific company in the current social environment. Society currently moves through a socio-technical revolution with man seeking higher levels of motivation. The transitory environment from an autocratic/paternalistic to a participative operating mode demands systems parameters only found to a limited extent in manufacturing systems today. It is claimed, that modern manufacturing systems design needs to be based on group working, job enrichment, delegation of decision making and reduced job monotony. The analysis shows how negative aspects of cellular manufacture such as lack of flexibility and poor fixed asset utilisation are relatively irrelevant and misleading in the broader context of the need to come to terms with the social stresses imposed on a company operating in the industrial environment of the present and the immediate future.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Computer-based simulation is frequently used to evaluate the capabilities of proposed manufacturing system designs. Unfortunately, the real systems are often found to perform quite differently from simulation predictions and one possible reason for this is an over-simplistic representation of workers' behaviour within current simulation techniques. The accuracy of design predictions could be improved through a modelling tool that integrates with computer-based simulation and incorporates the factors and relationships that determine workers' performance. This paper explores the viability of developing a similar tool based on our previously published theoretical modelling framework. It focuses on evolving this purely theoretical framework towards a practical modelling tool that can actually be used to expand the capabilities of current simulation techniques. Based on an industrial study, the paper investigates how the theoretical framework works in practice, analyses strengths and weaknesses in its formulation, and proposes developments that can contribute towards enabling human performance modelling in a practical way.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The performance of direct workers has a significant impact on the competitiveness of many manufacturing systems. Unfortunately, system designers are ill equipped to assess this impact during the design process. An opportunity exists to assist designers by expanding the capabilities of popular simulation modelling tools, and using them as a vehicle to better consider human factors during the process of system design manufacture. To support this requirement, this paper reports on an extensive review of literature that develops a theoretical framework, which summarizes the principal factors and relationships that such a modelling tool should incorporate.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This dissertation studies the process of operations systems design within the context of the manufacturing organization. Using the DRAMA (Design Routine for Adopting Modular Assembly) model as developed by a team from the IDOM Research Unit at Aston University as a starting point, the research employed empirically based fieldwork and a survey to investigate the process of production systems design and implementation within four UK manufacturing industries: electronics assembly, electrical engineering, mechanical engineering and carpet manufacturing. The intention was to validate the basic DRAMA model as a framework for research enquiry within the electronics industry, where the initial IDOM work was conducted, and then to test its generic applicability, further developing the model where appropriate, within the other industries selected. The thesis contains a review of production systems design theory and practice prior to presenting thirteen industrial case studies of production systems design from the four industry sectors. The results and analysis of the postal survey into production systems design are then presented. The strategic decisions of manufacturing and their relationship to production systems design, and the detailed process of production systems design and operation are then discussed. These analyses are used to develop the generic model of production systems design entitled DRAMA II (Decision Rules for Analysing Manufacturing Activities). The model contains three main constituent parts: the basic DRAMA model, the extended DRAMA II model showing the imperatives and relationships within the design process, and a benchmark generic approach for the design and analysis of each component in the design process. DRAMA II is primarily intended for use by researchers as an analytical framework of enquiry, but is also seen as having application for manufacturing practitioners.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This work attempts to create a systemic design framework for man-machine interfaces which is self consistent, compatible with other concepts, and applicable to real situations. This is tackled by examining the current architecture of computer applications packages. The treatment in the main is philosophical and theoretical and analyses the origins, assumptions and current practice of the design of applications packages. It proposes that the present form of packages is fundamentally contradictory to the notion of packaging itself. This is because as an indivisible ready-to-implement solution, current package architecture displays the following major disadvantages. First, it creates problems as a result of user-package interactions, in which the designer tries to mould all potential individual users, no matter how diverse they are, into one model. This is worsened by the minute provision, if any, of important properties such as flexibility, independence and impartiality. Second, it displays rigid structure that reduces the variety and/or multi-use of the component parts of such a package. Third, it dictates specific hardware and software configurations which probably results in reducing the number of degrees of freedom of its user. Fourth, it increases the dependence of its user upon its supplier through inadequate documentation and understanding of the package. Fifth, it tends to cause a degeneration of the expertise of design of the data processing practitioners. In view of this understanding an alternative methodological design framework which is both consistent with systems approach and the role of a package in its likely context is proposed. The proposition is based upon an extension of the identified concept of the hierarchy of holons* which facilitates the examination of the complex relationships of a package with its two principal environments. First, the user characteristics and his decision making practice and procedures; implying an examination of the user's M.I.S. network. Second, the software environment and its influence upon a package regarding support, control and operation of the package. The framework is built gradually as discussion advances around the central theme of a compatible M.I.S., software and model design. This leads to the formation of the alternative package architecture that is based upon the design of a number of independent, self-contained small parts. Such is believed to constitute the nucleus around which not only packages can be more effectively designed, but is also applicable to many man-machine systems design.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This thesis deals with the problem of Information Systems design for Corporate Management. It shows that the results of applying current approaches to Management Information Systems and Corporate Modelling fully justify a fresh look to the problem. The thesis develops an approach to design based on Cybernetic principles and theories. It looks at Management as an informational process and discusses the relevance of regulation theory to its practice. The work proceeds around the concept of change and its effects on the organization's stability and survival. The idea of looking at organizations as viable systems is discussed and a design to enhance survival capacity is developed. It takes Ashby's theory of adaptation and developments on ultra-stability as a theoretical framework and considering conditions for learning and foresight deduces that a design should include three basic components: A dynamic model of the organization- environment relationships; a method to spot significant changes in the value of the essential variables and in a certain set of parameters; and a Controller able to conceive and change the other two elements and to make choices among alternative policies. Further considerations of the conditions for rapid adaptation in organisms composed of many parts, and the law of Requisite Variety determine that successful adaptive behaviour requires certain functional organization. Beer's model of viable organizations is put in relation to Ashby's theory of adaptation and regulation. The use of the Ultra-stable system as abstract unit of analysis permits developing a rigorous taxonomy of change; it starts distinguishing between change with in behaviour and change of behaviour to complete the classification with organizational change. It relates these changes to the logical categories of learning connecting the topic of Information System design with that of organizational learning.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The research, which was given the terms of reference, "To cut the lead time for getting new products into volume production", was sponsored by a company which develops and manufactures telecommunications equipment. The research described was based on studies made of the development of two processors which were designed to control telephone exchanges in the public network. It was shown that for each of these products, which were large electronic systems containing both hardware and software, most of their lead time was taken up with development. About half of this time was consumed by activities associated with redesign resulting from changes found to be necessary after the original design had been built. Analysing the causes of design changes showed the most significant to be Design Faults. The reasons why these predominated were investigated by seeking the collective opinion from design staff and their management using a questionnaire. Using the results from these studies to build upon the works of other authors, a model of the development process of large hierarchical systems is derived. An important feature of this model is its representation of iterative loops due to design changes. In order to reduce the development time, two closely related philosophies are proposed: By spending more time at the early stages of development (detecting and remedying faults in the design) even greater savings can be made later on, The collective performance of the development organisation would be improved by increasing the amount and speed of feedback about that performance. A trial was performed to test these philosophies using readily available techniques for design verification. It showed that about an 11 per cent saving would be made on the development time and that the philosophies might be equally successfully applied to other products and techniques.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This study is concerned with several proposals concerning multiprocessor systems and with the various possible methods of evaluating such proposals. After a discussion of the advantages and disadvantages of several performance evaluation tools, the author decides that simulation is the only tool powerful enough to develop a model which would be of practical use, in the design, comparison and extension of systems. The main aims of the simulation package developed as part of this study are cost effectiveness, ease of use and generality. The methodology on which the simulation package is based is described in detail. The fundamental principles are that model design should reflect actual systems design, that measuring procedures should be carried out alongside design that models should be well documented and easily adaptable and that models should be dynamic. The simulation package itself is modular, and in this way reflects current design trends. This approach also aids documentation and ensures that the model is easily adaptable. It contains a skeleton structure and a library of segments which can be added to or directly swapped with segments of the skeleton structure, to form a model which fits a user's requirements. The study also contains the results of some experimental work carried out using the model, the first part of which tests• the model's capabilities by simulating a large operating system, the ICL George 3 system; the second part deals with general questions and some of the many proposals concerning multiprocessor systems.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The work described was carried out as part of a collaborative Alvey software engineering project (project number SE057). The project collaborators were the Inter-Disciplinary Higher Degrees Scheme of the University of Aston in Birmingham, BIS Applied Systems Ltd. (BIS) and the British Steel Corporation. The aim of the project was to investigate the potential application of knowledge-based systems (KBSs) to the design of commercial data processing (DP) systems. The work was primarily concerned with BIS's Structured Systems Design (SSD) methodology for DP systems development and how users of this methodology could be supported using KBS tools. The problems encountered by users of SSD are discussed and potential forms of computer-based support for inexpert designers are identified. The architecture for a support environment for SSD is proposed based on the integration of KBS and non-KBS tools for individual design tasks within SSD - The Intellipse system. The Intellipse system has two modes of operation - Advisor and Designer. The design, implementation and user-evaluation of Advisor are discussed. The results of a Designer feasibility study, the aim of which was to analyse major design tasks in SSD to assess their suitability for KBS support, are reported. The potential role of KBS tools in the domain of database design is discussed. The project involved extensive knowledge engineering sessions with expert DP systems designers. Some practical lessons in relation to KBS development are derived from this experience. The nature of the expertise possessed by expert designers is discussed. The need for operational KBSs to be built to the same standards as other commercial and industrial software is identified. A comparison between current KBS and conventional DP systems development is made. On the basis of this analysis, a structured development method for KBSs in proposed - the POLITE model. Some initial results of applying this method to KBS development are discussed. Several areas for further research and development are identified.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

As a new medium for questionnaire delivery, the Internet has the potential to revolutionize the survey process. Online-questionnaires can provide many capabilities not found in traditional paper-based questionnaires. Despite this, and the introduction of a plethora of tools to support online-questionnaire creation, current electronic survey design typically replicates the look-and-feel of paper-based questionnaires, thus failing to harness the full power of the electronic delivery medium. A recent environmental scan of online-questionnaire design tools found that little, if any, support is incorporated within these tools to guide questionnaire designers according to best-practice [Lumsden & Morgan 2005]. This paper briefly introduces a comprehensive set of guidelines for the design of online-questionnaires. Drawn from relevant disparate sources, all the guidelines incorporated within the set are proven in their own right; as an initial assessment of the value of the set of guidelines as a practical reference guide, we undertook an informal study to observe the effect of introducing the guidelines into the design process for a complex online-questionnaire. The paper discusses the qualitative findings — which are encouraging for the role of the guidelines in the ‘bigger picture’ of online survey delivery across many domains such as e-government, e-business, and e-health — of this case study.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

As a new medium for questionnaire delivery, the internet has the potential to revolutionise the survey process. Online (web-based) questionnaires provide several advantages over traditional survey methods in terms of cost, speed, appearance, flexibility, functionality, and usability (Bandilla et al., 2003; Dillman, 2000; Kwak and Radler, 2002). Online-questionnaires can also provide many capabilities not found in traditional paper-based questionnaires: they can include pop-up instructions and error messages; they can incorporate links; and it is possible to encode difficult skip patterns making such patterns virtually invisible to respondents. Despite this, and the introduction of numerous tools to support online-questionnaire creation, current electronic survey design typically replicates that of paper-based questionnaires, failing to harness the full power of the electronic delivery medium. Worse, a recent environmental scan of online-questionnaire design tools found that little, if any, support is incorporated within these tools to guide questionnaire designers according to best-practice (Lumsden and Morgan, 2005). This article introduces a comprehensive set of guidelines - a practical reference guide - for the design of online-questionnaires.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The chapter discusses both the complementary factors and contradictions of adoption ERP-based systems with Enterprise 2.0. ERP is well known as IT's efficient business process management. Enterprise 2.0 supports flexible business process management, informal, and less structured interactions. Traditional studies indicate efficiency and flexibility may seem incompatible because they are different business objectives and may exist in different organizational environments. However, the chapter breaks traditional norms that combine ERP and Enterprise 2.0 in a single enterprise to improve both efficient and flexible operations simultaneously. Based on multiple case studies, the chapter analyzes the benefits and risks of the combination of ERP with Enterprise 2.0 from process, organization, and people paradigms. © 2013 by IGI Global.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The research was instigated by the Civil Aviation Authority (CAA) to examine the implications for air traffic controllers' (ATCO) job satisfaction of the possible introduction of systems incorporating computer-assisted decision making. Additional research objectives were to assess the possible costs of reductions in ATCO job satisfaction, and to recommend appropriate task allocation between ATCOs and computer for future systems design (Chapter 1). Following a review of the literature (Chapter 2) it is argued that existing approaches to systems and job design do not allow for a sufficiently early consideration of employee needs and satisfactions in the design of complex systems. The present research develops a methodology for assessing affective reactions to an existing system as a basis for making reommendations for future systems design (Chapter 3). The method required analysis of job content using two techniques: (a) task analysis (Chapter 4.1) and (b) the Job Diagnostic Survey (JDS). ATCOs' affective reactions to the several operational positions on which they work were investigated at three levels of detail: (a) Reactions to positions, obtained by ranking techniques (Chapter 4.2); (b) Reactions to job characteristics, obtained by use of JDS (Chapter 4.3); and (c) Reactions to tasks, obtained by use of Repertory Grid technique (Chapter 4.4). The conclusion is drawn that ATCOs' motivation and satisfaction is greatly dependent on the presence of challenge, often through tasks requiring the use of decision making and other cognitive skills. Results suggest that the introduction of systems incorporating computer-assisted decision making might result in financial penalties for the CAA and significant reductions in job satisfaction for ATCOs. General recommendations are made for allocation of tasks in future systems design (Chapter 5).