To determine the capability of a process to produce products within tolerances, statistical process control techniques should be employed to monitor the receipt of raw materials and production process. Control charts and process capability index functions are used to determine if a process is capable of producing products within tolerances. This is where statistical process control SPC comes in.It will give operating official a tool to recognize when a special cause of variation has entered the process so that the special cause can be eliminated.
If no special-cause variation is found to be present, statistical process control SPC helps define the capability of the stable process to judge whether it is operating at an acceptable level. The ultimate goal of statistical process control should be to cut costs by the elimination of testing through the qualification of raw materials and production processes. They can also be used to detect changes that have changed the production process for the better. The reduction of variation in any process is beneficial. However, you can never eliminate all variation, even if the processes are working as intended.