This is a supply chain management question.

8. [8 points] Suppose Trader Pete organic grocery store wants to employ 4 cashiers for the checkout process for the peak hours of Saturday 1 pm - 5 pm. Assume the customer arrivals follow Poisson process and the service times follow an exponential distribution. Pete estimates customers will arrive to the checkout at mean rate of 6/min and the service rate for reach server is 2 per min. Pete would like the customers to wait no more than 3 minutes on the average. a. Option 1 is for each cashier to have his/her own line. What is the average waiting time in line for this option? b. Option 2 is to have one line leading to the pool of 4 cashiers. What is the average waiting time in line for this option? c. Which option meets the requirement of average waiting time no more than 3 minutes