Abstract

In this paper, the authors have investigated the effects components commonality and uncertainty in lead time, machine breakdown, etc. in a manufacturing environment. The production is characterized by multiple end items for multi-period and multi-stage dependent demand. The delivery performances, throughput of the finished products and average production time in the system are examined for different experimental scenarios with reference to an existing manufacturing setting. A simulation package, namely WITNESS is used to simulate/analyze the situations of the production lines. Simulation models are developed and these are verified and validated with the historical data collected from the company. It is observed that inclusion of common components in the manufacturing system is generally beneficial over the non-commonality environment, especially i) in uncertain situations, ii) for long procurement lead time of components and iii) when the number of parts increase in the system. Impacts of machine breakdown on system outcomes are higher than that of the lead time variation. The combination of uncertain factors has more impact on outcomes (throughput and average production time) compared to the individual factor. Commonality has a better control over the machine breakdown than lead time uncertainty.

Key words: commonality, WITNESS, uncertainty.