The manager of Café Java is trying to determine whether to hire another cashier for the morning coffee rush hour. Does she need one? Justify your answer using the simulation results obtained from five customers:
Use the following random number streams:
1st set: .25, .95, .47, .02, .17 . .
2nd set: .70, .89, .02, .46, .49
Assume that the inter-arrival times are exponentially distributed, with a mean of 1/λ = 1.5 minutes per customer. The ordering, preparation, and money collecting (i.e., total service time) is an upward ramp function with a minimum of 15 seconds and a maximum of 1 minute.
a. Develop the process generators.
b. As the first step in designing a spreadsheet to study the problem in depth, manually simulate the arrival of five customers. (Hint: This is a basic single-server queuing system.)
c. Determine the average waiting time, the average queue length, and the average time in the systems.
d. Based on these limited results, do we need another cashier? Justify.
e. How and why would you incorporate the demand for coffee into the simulation?