Control phase is the fifth and final phase of Lean Six Sigma projects. Following are the deliverable of this phase:
Control Plan or Process Management Plan is a document ensuring that a robust mechanism to monitor and follow-up is established before the solution is implemented. Most Lean Six Sigma projects don’t exist after a few years of implementation. Usually, it is because of a poor control plan. A control plan covers: which metrics will be monitored, method of monitoring, how often, by whom and what has to be done when they go out of control (aka Reaction Plan).
It is recommended to have a control plan that is easy to implement and sustain.
As a part of the control plan, the method of monitoring has to be specific. Statistical Process Control uses well known Control Charts or Shewhart Charts. A control chart, computes the lower and upper control limits as a threshold to monitor any process measures; like CTQ. As the threshold is breached, the reaction plan has to be triggered. As the name suggests, it is a chart that is based on the principles of statistics, and hence there are no false alarms. Instilling the discipline of creating control charts and monitoring as per Control Plan is part of the rigor of a Lean Six Sigma Green Belt.
The last deliverable of the Lean Six Sigma project is Benefits Computation and Closure. But before that, the project is monitored for enough time (2 weeks to 2 months) to ensure that benefits are sustained. When the Lean Six Sigma Team is satisfied with the results, then the improved process is formally handed-over to the process owner.
Financial and non-financial benefits are computed based on actual results, and a formal sign-off from the finance manager and sponsor is obtained. This will be the project closure.
The Lean Six Sigma team celebrates its success; distributes rewards for active team members; and finally the Six Sigma Green Belt Certification Ceremony is undertaken.