Statistical Process Control involves using statistical methods to monitor processes. Statistical Process Control may be applied to processes in many industries including healthcare, finance and manufacturing.
All processes are subject to variation. Statistical Process Control uses statistical methods to:
- ensure that the process is stable. This often involves confirming that the process output characteristics conform to a normal distribution with parameters that are constant over time.
- using statistical methods to monitor the processes for timely identification of 'special causes' that indicate a change in the statistical parameters
The main tools of SPC include control charts and Process Capability Studies.
Control charts are used to monitor the output of a process. They are used to give timely warning of 'special causes' entering the process. They generally monitor either the process mean, the process variation, or a combination of both.
Types of control chart include:
- X-Bar & R Control Charts U Charts
- X-Bar & S Control Charts CuSum Charts
- ImR (Individual Moving Range) Control Charts Tabular Cusum Charts
- Median Control Charts CuSum V Mask
- Given Value Control Charts Moving Average Control Charts
- p Control Charts EWMA Control Charts
- np Control Charts
- c Control Charts
- u Control Charts
Process Capability is a method used to demonstrate that a process is 'capable' of achieving the required specifications. Process Capability is measured using the indices Cp and Cpk.
For more information follow the link for Statistical Process Control in MiC Quality Six Sigma Glossary.