An Investigation into Stock Levels within a Group Technology Manufacturing System

Abstract

In this thesis, work in progress in a manufacturing system is discussed, highlighting the function of buffer stocks and the factors which determine their operating levels. A particular manufacturing system is analysed, half of which operates on a group technology system and this is used as a basis for studying the mechanism of work in progress and its raison d'être. Factors such as the method of production planning and control, product variety, transportation, space availability, cost of machine set-ups, cost of interest, have been found to affect work in progress (w.i.p.) levels. These factors are discussed and evaluated in economic terms where possible. An optimum operating level of work in progress is recommended for the particular system under investigation and the problems of implementing such recommendations are discussed. Following the investigation into w.i.p. levels within a specific manufacturing system, the importance of being able to determine the approximate optimum w.i.p. levels is emphasised and a methodology is developed for determining this in the general case of any batch manufacturing industry.