Manufacturing, Planning and Control in a Jobbing Environment

Abstract

The sponsoring organisation, George Ellison Limited, manufacturers of electrical switchgear, expressed concern that customers' orders were delivered late. Difficulties were also being experienced in controlling production. The nature of the electrical switchgear market was low volume, high variety products made to customers' requirements. The approach to the research was to conduct an initial study to define the project and its boundaries. The concept of dependent and independent demand for components of assembled products was explored and a material requirements planning philosophy developed. A comparison of the theoretical approach to the practice showed that the inherent assumptions in the literature were not valid for George Ellison products. A hybrid system was developed utilising time-phased material requirements planning and order-point techniques for those parts which were not controlled by the former method. Component manufacturing batch quantities were planned in relation to the degree of control required for each part. A proposal was submitted to the company Board of Directors recommending the implementation of a manufacturing control system, on a mini-computer, including order entry, inventory control, material requirements planning, shop floor control and costing to be implemented in three phases. The recommendations were accepted by the Board of Directors at the end of September 1977 and the first phase of the system was implemented in May 1978. The second and third phases were due to be implemented post March 1979, the termination of the project period. The new system provided the company with immediate benefits in reduced inventory levels and improved machine-shop throughput. The framework of material requirements planning provided the company with the opportunity to develop its information systems.