Suppose jobs arrive at a single-machine workstation at a rate of 20 per hour and the average process time is 2 1/2 minutes.
a) What is the utilization of the machine?
b) Suppose that interarrival and process times are exponential,
i. What is the average time a job spends at the station (i.e., waiting plus process time)?
ii. What is the average number of jobs at the station?
iii. What is the long-run probability of finding more than three jobs at the station?
c) Now suppose process times are not exponential, but instead have a mean of 2 1/2 minutes and a standard deviation of 5 minutes
i. What is the average time a job spends at the station?
ii. What is the average number of jobs at the station?
iii. What is the average number of jobs in the queue?