This is the third lesson in the iKNOW™ Troubleshooting Skills: Developing Logical Thinking Library. This lesson teaches participants to develop a troubleshooting plan to evaluate problems. The importance of schematics in troubleshooting, steps necessary to repair the problems, and prevention of future trouble is discussed.

This lesson introduces statistical process control (SPC) as a prevention method used to reduce quality costs. The lesson explains variability and shows how to construct a histogram to represent it. The normal curve is described as well as its probability and relevance to the philosophy of never-ending improvement.