Is–Is Not Analysis
A major benefit of the Is-Is Not Analysis is its documentation of circumstances leading to the problem as well as those not associated with the problem. In the Pease Industries example, the Is-Is Not Analysis allowed the team to eliminate potential causes in the Cause-and-Effect Diagram. Hoerl and Snee (2002, p 204) suggest that the results of the analysis be displayed in a table also showing possible causes and further action.We illustrate that display of the analysis results using knowledge gained by the author’s consulting experience.
Peach Pit Example
Packers located in the vicinity of peach farms purchase raw peaches and process them for use as ingredients in food products. Their processing includes removal of the skin and pits. They use high-speed machines to remove the pits. We will call these machines pitters. However, the best pitters leave some pits and pit fragments. Some packers use inspectors downstream of the pitters to remove pits and pit fragments left by the pitters. The picture on the left shows inspectors removing pits and pit fragments.
The following figure shows the processing sequence.
The following table shows the results of the Is-Is not analysis.
- Hoerl, R. and R. D. Snee (2002). Statistical Thinking - Improving Business Performance. Pacific Grove, CA, Duxburry
