Cash : A New Spc Scheme Based on Cluster Analysis in Excess Variety

Precise control of process has become increasingly important in today's high-tech industries owing to the shrinking feature sizes and complex process technologies. In particular, there are excess varieties involved in the process. In this paper, we proposed a methodology called CASH that is a new SPC scheme based on cluster analysis and Shewhart control charts to deal with excess variety process control. This CASH scheme is implemented in a LED factory and the result is satisfactory