SETTING SAFETY LEAD-TIMES FOR PURCHASED COMPONENTS IN ASSEMBLY SYSTEMS - A GENERAL-SOLUTION PROCEDURE

In a recent paper, Hopp and Spearman (1993) presented a model to deter mine optimal lead-times for purchasing components where the only manuf acturing operation is the final assembly. It is assumed that delivery times of the different components are normal variates. An approximate iterative solution procedure is presented that facilitates derivation of the optimal lead-times. Based on an approximation for the delivery- time distribution, an alternative solution procedure is proposed that results in closed-form expressions for the decision variables of the p roblem. Both simplicity and ease of calculation are achieved. Furtherm ore, the new procedure is extended to non-normal delivery-time distrib utions.