Problem 3.50 (Part Level Submission) The three most important quality attributes at Mike's Super Service fast-food restaurant are considered to be good food, fast service, and a clean environment. The restaurant manager uses a combination of customer surveys and statistical measurement tools to monitor these quality attributes. A national marketing and research firm has developed data showing that when customers are in line up to five minutes, their perception of that waiting time is only a few minutes; however, after five minutes customer perception of their waiting time increases exponentially. Furthermore, a five-minute average waiting time results in only 2% of customers leaving. The manager wants to monitor speed of service using a statistical process control chart. At six different times during the day over a period of 15 days the manager had an employee time customers' waiting times (from the time they entered an order line to the time they received their order) at random, with the following results: 1 Sample 1 2 6.1 3.2 3 6.0 4 3.1 5 4.2 5.6 6 7 6.1 Waiting Times (min) 2 3 4 5 6 2.8 4.7 3.9 5.2 5.5 6.8 8.0 5.8 5.3 4.3 5.0 6.1 5.0 5.5 4.8 8.0 6.3 5.1 4.0 7.6 3.8 5.4 4.6 5.0 6.1 6.5 6.0 7.4 8.0 5.0 7.6 6.4 5.5 5.1 8.6 3.3 5.5 5.7 5.7 5.1 4.8 5.1 9.3 6.2 5.3 5.8 5.4 5.1 5.0 5.9 2.9 1.6 4.8 6.1 5.3 6.3 5.4 5.7 2.1 3.4 3.9 4.2 4.9 5.6 3.7 5.3 4.1 3.7 5.8 5.7 3.6 2.4 5.4 5.5 3.9 8 2.0 9 6.8 10 4.7 11 3.4 12 4.5 7.4 13 14 15 5.7 6 (a) Your answer is correct. Compute the control limits for the above provided data for -chart in conjunction with an R-chart? (Round answers to 2 decimal places, e.g. 2.75.) - chart: UCL 6.85 LCL 3.59 R - chart: UCL 6.76 LCL 0 Comment on the overall capability of the process. is The process in control according to both control charts. (b) Management at Mike's Super Service restaurant wants customers to receive their orders within 5 minutes 1 minute, and it has designed its ordering and food preparation process to meet that goal. Using the process mean and control limits developed in (a), compute the process capability ratio and index, and indicate if the process appears to be capable of meeting the restaurant's goal for speed of service. Assume that 30 = 1.62. (Round answers to 2 decimal places, e.g. 2.75.) Process capability ratio Process capability index The process capable of meeting the restaurant's goal for speed of service