SPC is one of the fundamental methods within quality management and as such it has a long history of application. Unfortunately the quality of the application is - to say it lightly - not always very good. It should not be surprising that in this case the potential benefits are not achieved. We need to control our processes so that they are and stay statistically stable.

Once this has been achieved we can improve the process and increase process capability

QS Consult view and approach

Many companies start with SPC because of a customer demanding it. This is not bad as such but the risk exists that this turns into a "Show Program for Customers". It is best to avoid this if you want to get better as a company. Some tips when implementing SPC in your organization:

• The leadership of the company has to be involved and use SPC on the processes that they manage.
• Process Control is the goal, SPC one of many possible means.
• SPC can only be successful if you are willing to react to control chart signals, so also willing to stop processes when needed.
• SPC is most preventive if process parameters are controlled through an SPC chart.
• Pay sufficient attention to statistical stability. Only then the calculated control limits (and the calculated capability indices) have a predictive value.
• Use control chart signals also for other purposes (for instance to determine if maintenance is needed).
• There are different types of control charts: use the right chart at the right moment.

Services offered

• SPC training at various levels (from novice to specialist).
• Support on the introduction of SPC.
• Evaluation of the current use of SPC and possibilities for improvement.

Additional information

SPC in Paint Application: Mission Impossible?(Pdf)
Presentation at the 52nd Annual Quality Congress – 1998

Gives an example of integrating SPC with other methods in a complex process. With thanks to Volvo Cars Ghent.

MS Excel 2003 tool (Dutch version only!) for an Individuals, Moving Range kaart