LEMS

a$.=3$ customers$/$hour

$=5$ customers$/$hour

$M=1$

$(1)$ What is the system utilization?

$(2)$ What is the average number of customers waiting for service?

$(3)$ What is the average time customers wait in line for service?

Chapter Eighteen Management of Waiting Lines

b$.$ Repair calls are handled by one repairman at a photocopy shop. Repair time, including travel time, is exponentially distributed, with a mean of two hours per call. Requests for copier repairs come in at a mean rate of three per eight$-$hour day $($assume Poisson$).$ Determine the following:

$(1)$ The average number of customers awaiting repairs

$(2)$ System utilization

$(3)$ The amount of time during an eight$-$hour day that the repairman is not out on a call

$(4)$ The probability of two or more customers in the system