23.
Last year, the manager of the service department at East Woods Ford
instituted a customer opinion program to find out how to improve service.
One week after service on a vehicle was
performed; an assistant would call the customer to find out whether the work
had been done satisfactorily and how service could be improved. After a year of gathering data, the assistant
discovered that the complaints could be grouped into the following five
categories:
|
Complaint |
Frequency |
|
Unfriendly atmosphere |
5 |
|
Long wait for service |
17 |
|
Price too high |
20 |
|
Incorrect bill |
8 |
|
Needed to return to |
50 |
|
Total |
100 |
a.
Draw a bar chart and a Pareto
chart to identify the significant service problems
b) Categorize the following causes of complaints into a cause-and-effect diagram: tools, scheduling, defective parts, training, billing system, performance measures, diagnostic equipment, and communications.
24. Oregon Fiber Board makes roof liners for the automotive industry. The manufacturing manager is concerned about product quality. She suspects that one particular failure, tears in the fabric, is related to production-run size. An assistant gathers the following data from production records: Run Size Failures (%) Run Size Failures (%) 1 1,000 3.5 11 6,500 1.5 2 4,100 3.8 12 1,000 5.5 3 2,000 5.5 13 7,000 1.0 4 6,000 1.9 14 3,000 4.5 5 6,800 2.0 15 2,200 4.2 6 3,000 3.2 16 1,800 6.0 7 2,000 3.8 17 5,400 2.0 8 1,200 4.2 18 5,800 2.0 9 5,000 3.8 19 1,000 6.2 10 3,800 3.0 20 1,500 7.0
a. Draw a scatter diagram for these data.
b. Does there appear to be a relationship between run size and percent failures? What implications does this data have for Oregon Fiber Board’s business?
