Within the improvement phase, the critical root causes of process variability identified in the analysis phase are translated into "improvement interventions" or redesigned process steps or process corrections. This is the phase in which process changes are piloted with the proposed and improved interventions or corrective actions. There are statistical methods to test and verify that the root causes of process variations have successfully corrected process defects and improved process capability and outcomes. The measurement systems created within the measure phase will continue to gather data, which will be used to determine if the changes have had the desired impact on the process problem being targeted by the improvement project and team.
