A Study of Optimum Assembly Runs

Abstract

This paper reports on the formulation and application of a mathematical model of optimum assembly runs. The study was conducted in a large manufacturing firm and was concerned with the assembly and storage of expensive electronic equipments for use in commercial aircraft. The principle costs pertaining to this study involved the purchase of parts, internal parts fabrication, final assembly and inventories of raw materials, goods in process and finished goods. The most detailed consideration was given to assembly costs and these were derived directly from learmng curves which had been estimated from time-card records. Consideration was given to the effects on costs not only of varying the run size but also of varying the rate of assembly by altering the assembly time cycle. Thus the model includes as decision variables both the length of the run and the rate of assembly. It is formulated so that these decisions can be made simultaneously in a routine, clerical way. Finally, some remarks are made concerning the practical use of the model in the manufacturing operation.