Y=ƒ(X) It almost goes without saying that output is a function of input. During the Define phase, the project team identified the “big Y”; the key output or process that needs improvement. They also identified as many Xs , or inputs, as possible. The team then figured out what to measure and how, calibrated their instruments and began collecting data. During the next phase, analyze, the focus is on identifying the important Xs. How much impact does X1 have on Y? What does that tell us about how to improve the performance of Y?
A – Analyze
The Analyze phase is the time to start looking for the root causes of the issues that broke the process. The team will identify and verify the causes based on the data collected during the measure phase. Next they’ll separate the “vital few” causes from the “trivial many” and so focus their efforts and energy on only the high-impact causes. They will deploy a number of quantitative and qualitative tools to confirm they’ve captured all of the right causes to address in the upcoming Improve phase.
This is the time when Six Sigma teams run the greatest risk of jumping to conclusions. It’s important that the team set priorities, involve the affected stakeholders and avoid making assumptions. In order to determine what improvements to make the team needs to limit the causal factors in a meaningful way.
Some tools in use during the Analyze phase are:
- FMEA (Failure Mode Effects Analysis)
- Process maps
- Pareto diagrams
- Statistical tests used to limit causes
- Ishikawa diagram (root cause analysis)
- Multi-variate analysis
Next time, I’ll continue to break down the DMAIC process further.