Which of the following must be true before moving to the Control phase?

In the context of Total Quality Management (TQM) and the DMAIC (Define, Measure, Analyze, Improve, Control) process, moving to the Control phase is contingent upon several critical factors being fulfilled.

First, improvements must be implemented to ensure that the changes intended to enhance processes are actively in place. This foundational step is crucial as it sets the stage for monitoring the new methods or practices meant to deliver better outcomes.

Second, selecting an effective solution is a necessary prerequisite. This means that the team has thoroughly evaluated potential solutions and identified the one that offers the best chance of success for the problem at hand. Choosing the right solution is critical in making sure that the improvements will address the root causes effectively.

Third, there needs to be verification of the solution's effectiveness. This involves checking and analyzing results post-implementation to confirm that the changes are producing the desired improvements and that any processes or outputs are operating as intended. Verification helps in ensuring that the solution is not only viable in theory but also in practice.

Since all of these components are essential for a successful transition into the Control phase, where processes are standardized, monitored, and maintained to ensure ongoing success, it is accurate to conclude that all the listed criteria must be met before proceeding.