Managing for Quality and Performance Excellence 9th Edition by James Evans,William Lindsay

Exercise 24

Note: Data sets for several problems are available in the Excel workbook C07Data in the Student Companion Site for this chapter. Click on the appropriate worksheet tab as noted in the problem (e.g., Prob. 7-5, etc.) to access the data.
Bestronics has a three-step process for processing customer sales. First, the cashier must look up the customer's loyalty card on the company's information system. Second, the cashier enters the transaction on the point-of-sale register. Third, the cashier processes the credit card through a verification system.
a. If the reliability of the information system is 0.998, the reliability of the point-of-sale register is 0.992 and the reliability of the credit card verification system is 0.978, what is the overall system reliability?
b. If the store manager wants to ensure at least a 98 percent system reliability, make a recommendation of how to do this.