Statistical process control (SPC) in a high volume machining center : value of standard operating procedures

Abstract

Statistical process control is implemented in a high volume machining center to reduce scrap and improve the quality of production. New hires are working in a complex production environment with excellent metrology resources that can be used for real time inspection but there is a lack of standard operating procedures to help them use these resources. A methodology for implementation of statistical process control is developed and evaluated by implementing it in a section of the machining center which has the biggest benefit. Gages are evaluated and control charts are established in that section. Operators are trained in the standard operating procedures related to the different components of SPC. The standard operating procedures are developed to be portable such that SPC can be used in various sections of the machining center. Findings include cost saving benefits and scrap rate reduction of approximately 50% can be achieved for the entire machining center by the implementation of statistical process control. A training matrix is developed to train different people of the company on the concepts of SPC. Implementing SPC in a high volume machining center has proved to deliver value in reduction of scrap, quality improvement, ability to react to changes for the new hires and other benefits. Standard operating procedures have made a difference in the quality inspection of parts and in maintaining high quality standards that can make the machining center a world class manufacturer.