Answers to Review Questions

1. A. Common causes of variance are situations that are common to the process you’re using and are easily controlled at the operational level.
2. C. Inspection involves physically looking at the product results to determine whether the results are tolerable. Prevention keeps errors from reaching the customers or occurring in the first place, histograms plot information on a bar chart, and module testing is used in the information-technology industry to test programming code.
3. D. Pareto diagrams rank the importance of problems based on their frequency of occurrence over time. Control charts display the variance of several samples of the same process over time. Flowcharts depict the logical steps that must be performed to accomplish an objective, and Ishikawa diagrams show the relationship between cause and effect.