An Empirical Study of the Machine Assembly Efficiency Improvement Based on Lean Six Sigma Technique

Effectively controlling inventory is one of the key factors for small and medium-sized enterprises to make profit. Most small and medium-sized enterprises solve their problems through experience or trial and error, but they are often unable to achieve the desired enterprise performance under limited time and cost. The real case adopted herein covers a manufacturer of optical lens equipment, and the bottleneck is the shortened period of delivery caused by refunded, reduced, and delayed orders due to changes in the market. Under the framework of Lean Six Sigma, this study identified the key factors affecting working hours and product cycle and then formulates strategies to import the actual process. The results show that the inventory turnover rate increases from 20.8% to 41.6%, deriving a financial effect worth of NT$15.57 million. For the practical verification of the case company, Lean Six Sigma really does improve the assembly process efficiency, achieving a result beyond the expected target. With this successful case, this study can be a reference for other firms.