Problem 1

A gasoline station near a shopping mall has two self-serve pumps and one full-serve pump that services only handicapped customers, which is 10% of the calling population. Customers arrive at a rate of 1.6 customers per minute (that is, the arrival time interval follows exponential distribution). Service times have discrete distributions as follows: 

Each pump has a queue line. Customers will not wait if five or more cars are waiting in either line.

Tasks:

1) Draw a simulation flow diagram for this problem.

2) Simulate this system for an eight-hour period using excel and answer the following questions:

(1). What percentage of customers is lost?

(2). How many customers are served based on your simulation?

(3). Calculate the average waiting time per customer for self-serve service and full-serve service.

3) How might you improve this system if necessary and show evidence?