The goals of six sigma plan are established on the foundation of customer satisfaction such as Quality, Cost, Delivery and Service. There are many statistical evaluation methods, A more technical perspective is needed in estimating the effect of the Manufacturing Process for improving the Productivity, Process network analysis is a technique which has the potentiality for a wide use to improve the manufacturing process which other techniques can`t be used to analyze effectively. Six sigma model of manufacturing process can apply efficiently DMAIC that is general progress step to solve problems. This paper presents how to improve the manufacturing process by statistical process control using six sigma