Research of increasing productivity of the assemble line with six sigma way

Motorola在1980年代中期透過實施了六標準差方法，因而拉近了與日本企業的品質差距，同時也透過實施了六標準差方法，使得Motorola變得更有競爭優勢，之後奇異的其總裁傑克.威爾許更大幅地推動此套方法的普及，將六標準差全面的導入奇異的日常作業流程中，因此現在的六標準差，除了具備統計上的意義外，也代表著一套非常有系統的流程改善方法，甚至有些企業更以其作為企業策略與營運經營的方法，讓六標準差的應用範圍越來越廣。 本研究以六標準差改善手法的DMAIC步驟，來進行個案公司衛星廣播產品線UPA-ST組裝線的生產力提升。而在使用此方法之前，本研究則運用限制理論的思維來思考如何找出影響組裝線生產力的主要因素，因此本研究在界定的階段就發現了影響UPA-ST組裝線的生產力的關鍵因素主要有三項，第一項為瓶頸工站，第二項為工時變異大的工站，第三項則為組裝線未平衡的作業。針對各項關鍵因素，本研究透過數據的蒐集與分析來瞭解這三項關鍵因素如何影響組裝線的生產力，最後則透過了作業拆解與同步作業來提升了瓶頸工作站的生產力、透過了工站順序調動與合併來使組裝線能夠平衡、瞭解變異的來源與建立自主品檢流程來降低變異性大的工作站之變異，藉由減少這三項關鍵因素對組裝線生產力的影響，因此也使此條組裝線最後能增加產出與減少人力資源的投入，因而提升了生產力。Motorola used six-sigma way to shorten the quality difference in the middle of 1980s. Also, it became more competitive via six-sigma way. Then, the president of GE, Jack Welch, made much effort to popularize this way and implemented into this way to the daily process of GE. As a result, besides the meaning of statistics, current six-sigma also represents the set of systematic way to improve process. Further, some companies use it as strategies and operation ways. These cause the application of six-sigma way become more and more broad. This research use DMAIC steps of six-sigma way to increase the productivity of UPA-ST ‘s satellite broadcast product line. Before using this way, this research use limitation theory to think how to find the major factors which would influence the productivity of the assemble line. Consequently, this research finds there are three major factors to influence the productivity of UPA-ST’s assemble line: the first is the bottleneck station, the second is the station which exists big variance of working time, the third is the unbalance operation of the assemble line. For each major factors, this research uses data collection and analysis to understand how these three major factors affect the productivity of assemble line. Finally, it increases the productivity via taking apart the operation and synchronous way; it makes assemble line balance via adjust the order of work station and combination; it reduces the variance of the working station which exists big variance via understanding the source of variance and building the autonomous quality-control process. Through reducing the productivity influence of these three major factors, it consequently make the assemble line increase the output and reduce the input of manpower to increase the productivity