To evaluate a successful shift in a project, measuring the metrics before and after the implementation is crucial. It will then define, that the analysis and resolution of the problem were calculated and not by chance.
An instance where a suitable metric was required, is when company XYZ wanted to measure and evaluate why it was losing the sales of a specific chemical product.
3 ideas were identified in the process; consideration of the market share, quality variation of the viscosity, and the number of customer complaints per month.
The Lean Six Sigma process then started checking out the least inappropriate ideas for the primary project metric. The idea to consider the market share was rejected and so was the quality variation of viscosity.
Thus XYZ’s team settled on making the customer’s complain regarding poor unloading as the primary metric. It was because of two major; one, improved viscosity will eventually improve unloading, and that will satisfy the customers, and two, learning about the customers complaint in detail, will help the team mitigate the root cause.
Taking this instance as a learning, it is important to evaluate the metric chose as the primary metric will actually bring about a positive change, or not. Lean Six Sigma practitioners suggest studying a large amount the historical data to understand the system and the do the RCA. While this does work in most of the cases, it must not be the cause of delay in others.
The very well-known Hawthorne effect proves that process changes can even happen if the organization focusses simply on keeping the workforce motivated. Studying the sustainability of an improved project might be difficult, at times, because of the shifted focus of the leadership and the management.
Lean Six Sigma preaches that if a metric has been considered important enough to bring about a positive change, it should be monitored even after the project has transformed, leaders have changed, or the mean has shifted.