Question

A manufacturer uses statistical process control to control the quality of the firm's products. Samples of 50 of Product A are taken, and a defective/acceptable decision is made on each unit sampled. For Product B, the number of flaws per unit is counted. What type(s) of control charts should be used?

Answer 1

For Product A, a p-chart is used as it deals with a defective/acceptable decision which is attribute data. For Product B, a u-chart is suitable as it counts the number of flaws per unit, dealing with variable data.

Step-by-step explanation:

For Product A, where a decision of defective or acceptable is made on each unit, a control chart for attributes would typically be used, specifically a p-chart (proportion of defective items chart). This is because the product is being classified into two categories: defective or acceptable, which is a type of attribute data.

For Product B, where the actual number of flaws per unit is counted, a control chart for variables would be appropriate, and more specifically, a u-chart (number of defects per unit chart) would be the choice. This is because you are dealing with a count of flaws, which is variable data that can be measured on a continuous scale.

Answer 2

P- Chart for A

C- Chart for B

Step-by-step explanation:

P- Charts are the statistical tool in the form of charts which describes the share or proportion of non conforming, basically non acceptable units in the selected sample.

It only has pass/fail, yes/no types of tools to verify and describe the conditions satisfied.

C - Charts are the statistical tools, that counts the non conforming or non acceptable units, individually. It uses a count type technique. In this case also for Product B the flaws are counted per unit basis.