My project is almost done and the results are looking great, but I’m worried that the team will revert to their old ways once I stop monitoring them. What are some simple "Control" tools that a Yellow Belt can implement to ensure the process improvements actually stick long-term? I’ve heard of Control Charts, but are they too complex for a non-statistician?
3 answers
Mistake-proofing (Poka-Yoke) is the best control. If you can change the process so it’s impossible to do it wrong, you don’t even need to monitor it!
The biggest mistake is thinking the project ends when the improvement is made. For a Yellow Belt, the most effective control tools are often non-statistical. First, update the Standard Operating Procedure (SOP) and ensure everyone is trained on the new version. Second, implement Visual Management—like a simple dashboard or a shadow board—so anyone can see at a glance if the process is performing correctly. While a full X-bar Chart might be complex, a simple "Run Chart" (plotting data over time) is very easy to maintain and will show you immediately if the process starts to drift back to old levels.
Who is going to be the "Process Owner" responsible for maintaining these controls once you officially hand over the project and return to your normal duties?
David, that’s a great question. I’ve designated the floor supervisor as the Process Owner. Margaret, the "Run Chart" idea is perfect. I was overcomplicating things by trying to calculate upper and lower control limits. A simple line graph on the breakroom wall showing our daily error rate will keep the goal visible for everyone. I’m also creating a "Control Plan" document that outlines exactly what the supervisor should do if the error rate climbs above 5% for three days in a row.
Mary is absolutely right. Poka-Yoke is the "gold standard" of the Control phase. If you can build the quality into the process, it becomes self-sustaining.