Developing and implementing a statistical process control system in a small-sized company

In this thesis, first, the concepts of continuous improvement and statistical control were reviewed in detail. Then, information regarding seven quality tools and process/machine capability analysis, which are the basics of statistical quality control were presented. Next, related literatures about the applications of statistical quality control in various companies were demonstrated. Finally, a framework on statistical quality control for a small sized company, which is a supplier for original equipment manufacturers, was developed and implemented using the findings of the other researchers. In order to demonstrate that such a system can be developed and implemented in the company, a data set was gathered from the production process of a component, which is used for a work-in-process. According to a sampling plan, a data was gathered randomly on October 1st, 2005, and by using the data a histogram was drawn and a machine capability analysis was done for a lathe machine. For the current tolerances, it was concluded that machines were capable of producing right components. Then, on October 1st, 2005, 100 parts were picked up randomly between 8:30 and 18:30, and a histogram was drawn using the frequency distribution. Using the same data, process capability analysis was also done, and XBar and R charts were prepared. According to the results derived from the control charts and process capability analysis, to find why the process manufactured defective products, a brainstorming was done and a cause-and-effect diagram was developed. After the problems encountered in the first process capability analysis were resolved, 100 parts were gathered randomly on October 2nd, 2005, between 8:30 and 18:30. Using the new data, a histogram were drawn. Then, X-bar, R charts and the second process capability analysis were prepared. It was concluded that the process was in control and the parts were produced according to the specifications. Hence, the company was able to produce less defective products and better meet its customer needs implementing the proposed system. Another important conclusion derived from this research is that statistical control system can be used to increase competitive advantage even for small sized companies