Which step in the A3 process defines how to maintain improvements?

The step in the A3 process that focuses on how to maintain improvements is the follow-up phase. This step is essential for ensuring that the changes implemented are sustained over time. During follow-up, teams typically monitor the results of the implemented countermeasures, assess whether the improvements have led to the desired outcomes, and make adjustments as necessary.

By establishing a follow-up plan, organizations can create accountability and develop routines for periodic reviews of processes and performance metrics, ensuring that improvements are not only achieved but also preserved long-term. This is crucial in a continuous improvement framework like Six Sigma, where the goal is to not just fix problems but to embed improvements into the organization's culture and operations.

Other steps, such as background, countermeasures, root cause analysis, and current condition, play important roles in identifying problems and determining solutions, but they do not specifically address the ongoing maintenance and monitoring of improvements.