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

Exercise 6

Fred Read, the owner of the Freadilunch (pronounced Freddylunch) Restaurant, a suburban, quick service restaurant, was concerned about the loss of several regular customers. He measured the number of empty lunch tables from 11 A.M. until 2 P.M. over a four-week period. To better understand the reasons for the loss of customers, long lines, and dissatisfied patrons, Fred talked to several regular customers. He found that they liked the food and atmosphere of the restaurant, but felt that there were opportunities for improvement based on the lack of capability to quickly handle takeout orders (they had to be phoned in, not faxed), excessive time spent waiting for tables, inefficient service, surly waiters on certain days, and long lines at the cash register. He puzzled over how to sort out possible causes that led to these perceived problems. Fred also decided to design a check sheet to systematically gather data and determine which of these problems were the most significant. (Data for the check sheet information gathered for "Vacant Tables" and for "Customer Concerns" can be found in the Freadilunch 1 and Freadilunch 2 tabs in the Excel workbook C09Data.xlsx on the Student Companion Site.)
Plot the average number of empty tables on a run chart, computing the average value (center line), but ignoring the control limits. What do these data show?