The Development of a Computer Simulation Model of the Interaction Between the Supply and Usage of Major Components in Car Assembly for use in Stock Control

Abstract

The assembly of a motor car is the most capitally intensive part of its manufacture because there is high capital investment both in the stocks of expensive major components and in the fully automated assembly factories needed to produce ears. Control of major component stocks can therefore play a significant part in keeping overall manufacturing costs down. The nature cf volume car manufacture does not permit an, direct control of major component stocks, but a measure of indirect control can be achieved by fixing ceiling levels up to which stocks will be allowed to rise before supplies are stopped. At present these ceiling levels are not fixed in any scientific wey at the Austin-Morris Division of the British Leyland Motor Corporation, This thesis describes the development of a probabilistic computer simulation model of the inter-action between the supply and usage of major components in order to review major : | component stocking policy to the Company's best advantage. Part I of the thesis describes motor car manufacture ‘ and methods of production and inventory control of major components presently employed by the Company. “The contribution : of existing literature is also reviewed in this section of the | thesis. A simulation model of the inter-action between the supply and usage of major components is developed in the second part of the thesis. Part III deals with a feasibility study undertaken to validate, and experiment with, the model. The results obtained indicate that 1) The model used is sufficiently valid for its intended purpose; 2) The use of a ceiling level of about 2,000 sets of major components can be recommended for conditions specified in the feasibility study; 3) Maintaining a low ceiling level of about 700 sets of major components would cost over £170,000 more than the recommended level under similar conditions,