Value Stream Mapping is a material & information flow map. It’s also a tool for visualizing processes that need improvement.
A Cause and Effect Diagram (aka Ishikawa, Fishbone) showing possible causes (process inputs) for a given effect (process outputs).
Of the four Scales of measurement (Nominal, Ordinal, Interval, and Ratio), Ratio scales are ideal for Six Sigma projects.
Not all statistics are the same. It’s useful to discern between the various types of statistics when doing analysis.
One Sample T Hypothesis Test (Student’s T Test) are used to resolve hypothesis tests around comparing process means ( sample size to be <30)