Service Analysis Quiz 1

Sales at the local ice cream shop are handled by one server.  Customer arrivals are random (following a Poisson distribution) and the average arrival rate is 21 customers per hour.  A study of the service process shows that the average service time is 2 minutes per customer, with a standard deviation of 1.2 minutes.

1. What type of queuing system best describes this problem?
2. What are the mean interarrival and service times?  What are the standard deviations for the interarrival and service times?  What are the coefficients of variation for these processes?
3. Calculate the average waiting time in the ice cream shop.
4. Suppose the average waiting costs for customers (both in line and while they are being served) is $5.00 per hour, and the wage rate for the clerk is $7.50 per hour.  Should the owner hire another server?  Explain your answer.