The Six Sigma Black Belt Handbook

The primary purpose of the Measure phase is to answer the question, "How are we doing?" In other words, the team must baseline the current state of each CTQ or CTP. Many times in a project, the critical measure identified by the team is not an already reported measure. Although the team may not think the measure is meeting the goal, they need to collect data to verify the current performance level.
The deliverables from the Measure phase include:
x data to be collected
Operational definitions
Data collection plan
Measurement system analysis
Baselined data
This chapter discusses these deliverables as well as other tools and important for the Measure phase.
The team will have already picked the process outputs - CTQ's and CTP's, or the little y's - in the Define phase. The x's are process and input variables that affect the CTQ's and CTP's. The first consideration in the Measure phase is to identify the x data to collect while baselining these y variables. The y data are needed to establish a baseline of the performance of the process. The x data are collected concurrently with the y's in this phase so that the relationships between the x's and y's can be studied in the Analyze phase.
There are a variety of ways to identify the other data to collect (the x's). One of the best ways is to use a combination of the...