Statistical process control allows for maintaining certain standards without inspecting and regulating every step and product of the process. Similar to statistical quality control, SPC is utilized in manufacturing and service applications. It allows a series of steps designed to produce a repeated and consistent result, or process, to remain autonomous from constant oversight. SPC can be used in such varied environments as chemical processes or information management. Although the product and steps may be different, the statistical analysis of the process remains consistent.
Effects on Production
An advantage of SPC over other control methods is that production is less affected. There is less interruption and process slowdowns than with more direct examination and inspection methods. The leading variable in maintaining an SPC work environment is determining the necessary statistical sampling. Constant sampling of every aspect of the process defeats the purpose, but statistical analysis with long sampling intervals can allow discrepancies and poor quality results to slip through. When implementing an SPC system, the sampling should at least represent traditional quality issues already established.
Control Charts and Experiments
SPC relies heavily on control charts, continually improving the statistical analysis, and experiments designed to create possible variations for additional statistical results. Control charts track the various causes and solutions for statistical variations. The control chart results and ongoing experiments provide the necessary information for continually improving the statistical model for the process.
Effective Application of SPC
It is important to not let the analysis hinder productivity. Apply SPC as an adjunct to the process to analyze and produce data necessary for improvements. When it becomes the center of management and operations, then the process may suffer. Use SPC as a tool to improve the process; do not use the process to improve SPC methods and procedures.
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