These exercises are intended to give you experience writing and running GPSS/H simulation models. For each exercise you should submit the following:

• a printed or electronic version of a neatly composed GPSS block diagram model of the system, plus
• a plaintext email clearly giving any answer or observation required by the exercise, including references to the exact part of your simulation output (i.e. the listing file) that supports your answer, plus
• a plaintext attachment that is your complete listing file(s), and
• make sure your name and student ID# are included with your submission(s).

Exercise 1: At a one-chair barbershop, the interarrival times (in minutes) between customers is uniformly distributed between 15 and 25 minutes. 85% of the customers want just a haircut while the remaining 15% want both a haircut and a shave. Haircuts take between 13 and 27 minutes and shaves take between 15 and 25 minutes (where all times are uniformly distributed). Simulate the barbershop for a nine-hour day and determine the following:

1. the number of customers served in the nine hours
2. the average time a customer spends in the shop
3. the number of customers still in the shop after nine hours of operation

Exercise 2: A subway station has two entrances. Passengers arrive at entrance 1 at the rate of one every 10 +/- 5 seconds and move along a corridor that takes 15 +/- 5 seconds to walk. At entrance 2, passengers arrive at the rate of one every 5 +/- 2 seconds and walk along a corridor taking 20 +/- 8 seconds. The two streams of passengers merge to pass through a third corridor for 5 +/- 3 seconds and at the end, 60% turn for the northbound platform with the rest proceeding to the southbound platform. Simulate the arrival of the first 1000 passengers at the southbound platform starting from an empty system. Determine how many passengers have arrived at the northbound platform after the first 1000 have arrived at the southbound platform.

Exercise 3: Parts that are manufactured at the rate of one every 50 +/- 10 seconds go through an inspection that takes 30 +/- 10 seconds. The inspector passes 85% of the parts. Of the remaining 15%, one third (5%) are scrapped with the rest sent for reworking which takes 100 +/- 30 seconds, then the reworked parts are once again inspected with the same probability of rejection. Determine the number of parts that have to be reworked in the time that it takes for the first 500 parts to pass inspection.

Exercise 4: Customers come to a three-chair barbershop at the rate of one every 2 to 8 minutes (uniformly distributed). The shop can hold at most five customers, including those being served and those waiting. If the shop is full, arriving people go elsewhere. There are three barbers, and customers are served in order of their arrival. Customers like the first barber best, and the third barber least. If there is a choice, customers choose a barber according to their preference, but will not wait if any barber is available. A haircut takes between 5 and 15 minutes (uniformly distributed). Simulate 100 haircuts and determine the following:

1. the number of customers who go elsewhere
2. average time people spend in the shop (not including those who go elsewhere).
3. the number of customers served by each barber

Exercise 5: Trucks arrive at a dock at the rate of one every 9 +/- 3 minutes. The dock can hold 3 trucks and if there is no room when one arrives, the truck will come back 15 +/- 5 minutes later to try again. There is one forklift operator that takes 8 +/- 4 minutes to unload each truck. Simulate the unloading of 100 trucks and determine how many times a truck has to go away without being unloaded. In addition, determine how many trucks go away more than once before being unloaded. Finally, what is the most number of times any one truck has to go away and return before being unloaded?