Proceedings of the Institution of Mechanical Engineers,Part B: Journal of Engineering Manufacture

GEC ALSTHOM Large Machines Limited is a traditional heavy engineering company specializing in electrical machines (Fig. 1), and has successfully evolved over 90 years of operation. This historical success, however, led to a very functionalized layout of workshops and facilities totally unsuited to the present dynamic world market.

Through a company-wide improvement programme the company has been restructured within the existing buildings and site to take advantage of the latest cellular technology, using numerous innovative concepts in manufacture and adoption of just in time (JIT), total quality management (TQM) and design for manufacture (DFM) concepts in a low volume manufacturing environment.

The project involved the complete redesign of the factory layout, introduction of new products and equipment and concepts, resulting in dramatically improved leadtimes, inventories and sales per employee.

The case study is probably unique in that the programme was executed while increasing full production and involved the adoption of techniques often only associated with volume manufacture.

This paper is a review of some of the problems facing manufacturers of current and future generation electronic products. It presents a brief overview of work carried out by the Interconnection Group at Loughborough in the support of manufacturing industry, and in particular defines some of the limitations of the manufacturing processes. The paper closes by identifying research areas that can be addressed by the academic community to assist industry in its efforts to maintain competitiveness. Research areas focused on are conventional packaging, multi-chip modules and some aspects of the organization of international manufacture.

The role of the coordinate measuring machine within the inspection process has changed throughout its brief development. With its integration with industrial computer aided design (CAD) systems, its role is to change yet again. This paper presents the difficulties and limitations of current practice and identifies the inputs and decisions that need to be made within an integrated manufacturing environment.

A research programme was undertaken to investigate an approach based upon intelligent communications between systems. This led to the creation of a demonstration system that was employed in the measurement of industrial components. A case study, using a standard test block, is included to illustrate the processes undertaken. This includes feature identification, probe calibration and selection strategies and automatic re-routing to minimize changes in probes and orientations.

It is proposed that the approach demonstrated can be incorporated within a concurrent engineering environment to provide feedback and information about machine adjustments through a constraint modelling process.

Quality inspection is the source of vital information for business control and improvement in manufacturing. This paper describes research at the University of Bristol, in collaboration with Rolls-Royce plc, to develop automated inspection planning and computer aided inspection applications. The inspection planning system involves the representation of inspection features and the manufacturing process model, together with an automated planning mechanism driven by rule-based plan reasoning. The shop-floor computer aided inspection workstation uses hand-held instruments interfaced to a computer, and provides flexible, interactive assistance for the dimensional inspection task. Batch and component traceability and control, together with a range of quality information storage and reporting functions, are provided.

The Design System mfk will support the designer by an object-orientated synthesis of parts and an integrated knowledge-based analysis. An own-product model which is completely independent from the data structure of the used computer aided design (CAD) system contains all necessary information on geometry, technology, function and organization. It allows different types of analysis: design for production, tolerance analysis, cost and stress calculation, repeated component search, etc. Usable for products of higher complexity the Design System can be seen as an approach to an engineering workbench.

This paper describes the structure and operation of a low-cost computer aided design system for press tool design (CAPTD). The system is a collection of integrated industry standard microcomputer packages and purpose-built programs. The packages include AutoCad 11, for the input of workpiece geometry and the output of the press tool part and assembly drawings, and dBase IV for the decision support, the selection of press tool components and generating output reports. A purpose built ‘C’ program is also developed for the layout and nesting of the workpiece. The system is driven by a set of press tool design rules implemented in both the dBase IV and ‘C’ programming languages. The system is developed to run on 80386SX or higher based IBM-compatible microcomputers.

The surfaces produced by two different jet cutting processes, namely abrasive waterjet (AWJ) cutting and laser machining, are characterized for a comparative study. The surface profile measurements from experiments are modelled using auto regressive moving average (ARMA) models. The characteristics of the different profiles are identified by analysing these models. To describe the surface adequately, a sufficiently large sized sample is utilized for modelling. A novel method for identifying ARM A models based on the concept of model distance, which is ideal for large size samples, is adopted here. The relative advantages of this method are quantified in terms of the accuracy ratio. The profile characteristics (both dynamic as well as static) reveal more information about the nature of these processes. Scanning electron microscope (SEM) photographs of the surfaces generated by laser and AW J are analysed to obtain more insight into the physics of these processes.