Managing for Quality and Performance Excellence 10th Edition by James Evans ,William Lindsay

Exercise 39

Note: Data for many of the problems in this chapter can be found in the Excel workbook C08Data.xlsx on the Student Companion Site. Click on the appropriate worksheet tab as noted in the problem (e.g., Prob. 8-6, etc.) to access the data.
SpeedyNetService.com, an Internet service provider (ISP), is concerned that the level of access of customers is decreasing due to heavier use. The proportion of peak period time when a customer is likely to receive busy signals is considered a good measure of service level. The percentage of times a customer receives a busy signal during peak periods varies. Using a sampling process, the ISP set up control charts to monitor the service level, based on proportion of busy signals received. Construct the p -chart using on the sample data in the table in the worksheet Prob.8-43 in the C08Data.xlsx file on the Student Companion Site for this chapter. What does the chart show? Is the service level good or bad, in your opinion?