12.6 Which type of control chart?

For each of the following process outcomes, indicate if a variable control chart or an attribute control chart is most applicable:

12.7 Describe a process.

Each weekday morning, you must get to work or to your first class on time. Make a flowchart of your daily process for doing this, starting when you wake. Be sure to include the time at which you plan to start each step.

12.8 Common cause, special cause.

Each weekday morning, you must get to work or to your first class on time. The time at which you reach work or class varies from day to day, and your planning must allow for this variation. List several common causes of variation in your arrival time. Then list several special causes that might result in unusual variation, such as being late to work or class.

12.9 Pareto charts.

Continue the study of the process of getting to work or class on time. If you kept good records, you could make a Pareto chart of the reasons (special causes) for late arrivals at work or class. Make a Pareto chart that you think roughly describes your own reasons for lateness. That is, list the reasons from your experience, and chart your estimates of the percent of late arrivals each reason explains.

12.10 Pareto charts.

Painting new auto bodies is a multistep process. There is an "electrocoat" that resists corrosion, a primer, a color coat, and a gloss coat. A quality study for one paint shop produced this breakdown of the primary problem type for those autos whose paint did not meet the manufacturer's standards:

Make a Pareto chart. Which stage of the painting process should we look at first?