The Study on progressive die replacement for single die in furniture wheel manufacturing

Abstract

From the study of wheel manufactring, stamping work is playing a major role in producing wheel component parts. Effective die is therefore highly necessary. In the case study, single die is currently being used, for example, in making wheel frame, it needs 4 machines, 4 dies with 4 operators. Consequence problems are an area restriction, work in process increase, transportation between process increase when there are different model to be produced. As the above problems, this thesis is to study progressive die replacement by focusing on design, economic, performance improvement. After studying the current situation, there are 3 steps of proceeding. Step 1 Design plan It is to consider the part to be designed with the limitation of progressive die, then design process on strip sheet, after that calculation working force, and finaliy design die on Auto CAD. Step 2 Cost of replacement Investment cost : There are 2 items 1. Die 2. Equipment (regardless machine). For die making, the costing calculation is represented in breakdowqn cost ie. cost of labor and cost of material (design is excluded) whereas supporting equipment is called from price index in 2002. Operating cost : Direct labor cost and material cost is directly calculated. for overhead cost, sinc it is not existing yet, the overhead is then calculated based on history record by the statistic method "the relation of linear regression" of prograssive die company's benchmarking. Step 3 The study of performance It is to consider on key performance indicator such as cycle time, lead-time, unit per hour and other related problems in the factory such as area, work in process, man power, set up time. After studying the replacement, the performance is much better. It increase efficiency because lead time and set up time reduce about 60%, unit per hour increase 52%, area occupied reduce 75%, manpower reduce 23%. For the cost analysis, the result shows progressive die has an advantage profits in operating cost over thans single die, while investment cost is outstanding. However this investment will be recovered by operating profit and interest (time value of money) within 3 years. Therefore, from the year3-5, it will build up a profit as die life is in 5 years time.