Introduction to Management Science 12th Edition by Bernard Taylor

Exercise 4

In Problem, when the students come back for fall semester, the Sub Shop experiences a large increase in demand for about a month before it begins to level off again, such that the number of phone orders increases to an average of 8 per hour (Poisson distributed). If the shop now assumes that service times are exponentially distributed, with a mean of 20 minutes, how many delivery people will it need to provide a reasonable service level
Problem
The College Avenue Sub Shop is located in a small college town. Virtually all of its phone delivery orders are in the evening, between 5:00 p.m. and 1:00 a.m., so the shop has a delivery person for that time period. It receives an average of about 3 orders per hour (Poisson distributed). However, because of the different distances the delivery person must travel, the service time is undefined, with a mean of 15 minutes and a standard deviation of 6 minutes. Compute L , L q , W , and W q.