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Remaining Time: 22 minutes, 27 seconds. Question Completion Status 0 0.01656 QUESTION 5 The service time for customers coming through a checkout counter has mean 1 5 minutes and variance 1 minutes. Find the probability that the average (mean) service time for 100 customers to get service will be less than 1 2 minutes. O 0.0017 O 0.0712 0 0,0028 0 0.0013 QUESTION 6 The following information represents age x.(In months) and weight y,(In lbs) of 12 children. 057Lambda - Arrival Rate (Calls per Minute) Mu - Service Raie(Calls per Minute) Servers 11: Time Server Bus rho Probability of 0.503 0.333 0.1 10 0.030 0.01 2 0.0003 0.00003 In the s stem CUSTOMERS CUSTOMERS CUSTOMERS 0.74 0.07 0.03 0.01 TIME (Minutes) TIME (Minutes) TIME (Minutes) Time in System t(s) Y 4.33 4.38 Time in Line -I Y 0.53 0.03 TIME (Seconds) TIME (Seconds) TIME (Seconds) Time in System I(s) Y 239.7 201 .5 Time in Line I Y 31.7 3.5 Number in System n(s) Number in Line n I Y Y The purpose of this exercise is to discuss the situation facing a manager and help her determine how many servers to use and what the characteristics of the system will be. Endeavor Communications, a long distance provider, is reevaluating its account management department for handling customer service questions and requests. During the 6:00 pm to 10:00pm time period, past data hat calls to the account management department occur at an average rate of one call every 6.5 minutes. A study of past service times indicate that the average time to process a caller's question/request is 4.3 minutes. Like other phone systems, when a call comes in and all the servers are busy, the caller hears a message telling them to hold until the next server is available Top management at Endeavor Communications understands that the staffing decision involves the analysis of trade-offs. Increasing the number of servers will reduce the waiting times and increase the probability of immediate service at a higher cost with more idle time for the servers. Management has decided that the GOAL of the account management department is to immediately answer and service at least 90% of the incoming calls during the busiest time period of 6:00 to 10:00pm. They have asked you to determine the staffing level that will help them meet this goal. Also, they'd like you to provide your own recommendations. 1. What are the arrival and service rates in Calls per MINUTE? Use the spreadsheet to calculate these: A. (calls per minute) = (calls per minute) = 2. Since you are not required to perform the calculations in the case of multiple servers, you are provided with these results in the table that follows. You DO need to determine the information for the case of one server and RHO for 2 and 3 servers, Please fill in the chart below based on the numbers you calculate using your EXCEL FILE which can be found under LabEx Files on the course webpage. USE THREE DECIMAL PLACES IN ALL PROBABILITIES Servers 2 3 % Time Server Busy (rho) Probability of 0.503 0.515 0.333 0.341 0.110 JAWN-O 0.113 0.036 0.025 0.012 0.005 0.0003 0.001 0.00003 0.0003 In the system CUSTOMERS CUSTOMERS CUSTOMERS Number in System n(s) 0.74 0.67 Number in Line n(0) 0.08 0.01 TIME (Minutes) TIME (Minutes) TIME (Minutes) Time in System t(s) 4.83 4.36 Time in Line t() 0.53 0.06 TIME (Seconds) TIME (Seconds) TIME (Seconds) Time in System ((s) 289.7 261.5 Time in Line t() 31.7 3.5 These may be helpful----ONE SERVER FORMULAS: Pa = (1-p)p P. Vu ns= 2/(p=1) ni= p[2/ (H-X)]= phs ts = 1/ (H-1) to= p[1/ (H-X)]=ptsif a. a. Most of the dissatisfied customers do not speak, but just vote by their feet. True ! False b. b. Involving a manager in recovery process results in insufficient recovery. True r False c. c. Early detection in service recovery is importants especially for the customers who do not complain. True r' False Open-ended Questions: 1. 1. Why is service recovery important? 1 2. Why restaurants are important in service failure studies