Business Decision Analytics under Undertainty (33:136:400) 
Professor Eckstein
Simulating a Computing Help Desk Service

The IT department of your (large) company maintains a "help desk" service for computing problems.  On average, calls come in to the help desk every 3.5 minutes.  Calls are held in queue until a regular help desk staffer is available.  Once a call is connected to a staffer, the service time has a triangular distribution with a minimum of 1 minute, a most likely time of 5 minutes, and a maximum time of 15 minutes.  After servicing by a regular staffer, 35% of calls need to be passed along to a security specialist.  Such calls are held in a separate queue until a security specialist is available.  Once a call is assigned to security specialist, service time has a triangular distribution with a minimum of 10 minutes, a most likely time of 15 minutes, and a maximum of 25 minutes.

Regular help desk staffers cost $70 per hour, whether or not they are busy with a call.  Security specialists costs $90 per hour, whether or not they are busy with a call.  The firm assigns a cost of $80 per person per hour to time spent waiting on the phone for help.

Suppose that you have three regular help desk staffers and three security specialists available.  Simulating 100 hours of operation with a "warm-up" time of three hours, answer the following: