Development of a material management system for hard disk drive manufacturing

Abstract

This thesis concerns the development of a material management system for hard disk drive manufacturing. The objectives are to improve the service levels, on time delivery, and production resource utilization. The developed system consists of procedures and frameworks for managing individual items and a set of software that supports the procedures. The research starts from collecting part supply information in many aspects for the analysis of current situation. By using the element check list and cause and effect diagram, the causes of the problem are identified together with the solution concepts. The system established for managing materials employ the MRP concepts. Some special considerations that are addressed in this system include the following: 1.Make-buy decision is included in MRP for items that maybe outsourced in order that the production resources are utilized to the fullest. 2.Various lot sizing policies are applied to different items in MRP to minimize inventory costs. 3.Scrap Allowance for each item is established with statistical method to improve its availability for production. 4.Short-notice changes of product requirements that often occur in current practice make MPS unrealistic and cause serious problems in production performances. A demand policy, which establishes a frozen zone in planning horizon, is suggested to make MPS more realistic and stable. The comparison between the existing and the developed material management system shows that there are significant improvements on service levels, on time delivery of products, production resource utilization, and total inventory costs. The improvements of service levels and delivery performance are contributed by proper scrap allowances, which improve material availability. The improvement of production resource utilization performance is contributed by proper make-buy decision. Lastly, the improvement of total inventory costs is contributed by MRP and its proper lot sizing policies. Even better results are possible if a frozen zone in planning horizon is established.