The implementation of a fabrication cell and the optimisation of a pull system with a decision support system

Abstract

Manufacturing Resource Planning (MRPH) systems are used by forty per cent of UK manufacturing companies (Little, 1990). In cases where the implementation of the system was successful the companies have experienced reductions in inventories and lead times but the results were not always as good as they were anticipated. The justification of the major capital expenditure that is required for the implementation of the MRPn system was not always achieved by the benefits gained. Meanwhile, Just in Time (JFI) manufacturing environments experience benefits in terms of rapid stock- turns, due-date compliance and quality that MRPH users could not resist. This research initially focused on the investigation of the reasons of failure of MRPH implementations in low volume high variety manufacturing environments. The main reason being that the implementation of the MRPH system was not complemented by a shop floor re-organisation. The thesis reports an investigation and some elements of implementation of a change in the manufacturing operations of a company. The manufacturing environment that was used for this investigation was Reyrolle Switchgear Ltd. The production control system used by the company is MRPn, however, the implementation of the system was not as successful as it was anticipated. In order to cope with excessive stock, management decided to introduce a pull system for controlling the production of a limited number of components. The application of the pull system was limited because of the complexity in controlling the response of the manufacturing facilities, which had a functional layout. In order to establish an effective pull system, cellular manufacturing was introduced. The methodology used was "Line Analysis" which is a sub technique of "Production Flow Analysis". The pull system was complemented by a Decision Support computer based system in order to facilitate and enhance planning and inventory control. The changes were implemented and considerable improvements were achieved. The candidate is a researcher/investigator partly promoting the changes reported, implementing methods and investigating their effect.