An Introduction to Management Science 13th Edition by David Anderson,Dennis Sweeney ,Thomas Williams ,Jeffrey Camm, Kipp Martin

Exercise 31

A Florida coastal community experiences a population increase during the winter months with seasonal residents arriving from northern states and Canada. Staffing at a local post office is often in a state of change due to the relatively low volume months. The service rate of a postal clerk is 0.75 customer per minute. The post office counter has a maximum of three work stations. The target maximum time a customer waits in the system is five minutes.
a. For a particular Monday morning in November, the anticipated arrival rate is 1.2 customers per minute. What is the recommended staffing for this Monday morning? Show the operating characteristics of the waiting line.
b. A new population growth study suggests that next two years the arrival rate at the post office during the busy winter month can be expected to be 2.1 customers per minute. Use a waiting line analysis to the post office manager.