The purpose of an effective statistical process control is to control process variation and to improve process performance by using valid statistical methods of analyzing data gathered from tlıe process. Process control study consists of S steps. The first step is a selection of an appropriate process. The second step is an examination of tlıe “state of control” of the process to determine whether or not process is statistically under control The next step is a process capability study which shows whether the remaining variations after carrying out the second step are acceptable and whether the process will generate products and Services which match the specifted requirements. The fourth step is standardization of the process and maintaining it under control using control chart and other methods. The last step is an improvement of the process.