Control (DMAIC Step)

The control step of the DMAIC process is where changes are locked in place. The control step requires a system to measure the performance of the new process to ensure it is performing as expected.

The full DMAIC process is:

• Define
• Measure
• Analyze
• Improve
• Control

Without the control step, there would be no way of knowing if changes were effective. It is the most neglected step of any process change. Teams normally work hard to put the new process in place, and then disband. The people performing the new process seldom have the resources to make any additional changes or modification to the new process that might be needed. Busy operators have a tendency to want to revert to the old way of doing things when there is a problem. The control step of DMAIC is intended to prevent that.

The duration of the control step depends on how robust the process is. In many cases, monitoring the new process shows no problems. When this happens, there is little need to waste resources watching the changes.

Often, though, the control step of the DMAIC process shows fluctuations, indicating that more stability is needed, or that some problems have not been resolved. Obviously, follow-up actions are warranted in those cases.

Thorough documentation is critical to the control step. Data collection is often accomplished with check sheets. Run charts and the more sophisticated control charts are both methods to monitor a process for variation.