Analyzes the difference between the observed process mean at two settings of an input. To use a 2-sample t-test, you must collect a sample of data at both levels of the input variable.
|When to Use||Purpose|
|Mid-project||Fixing an input at two different settings (levels) helps determine which inputs have significant influence on the mean of the output.|
|End of project||Verify a significant difference exists between the means of the pre-project process and the post-project improved process. Of course, this assumes that one of the goals of the project was to shift the location of the process (change the process mean).|
Continuous Y (output), a single X (input) at two levels