You’re managing a playhouse showing off Broadway musicals and dramas. For the evening shows, customers arrive at the rate of 100 per hour and the ticket seller spends 30 seconds with each customer, which includes providing the ticket, validating parking and punching frequent watcher cards. You’re concerned because many customer are not seated until after the orchestra overture.
What is the average customer time in the system?
What would be the average customer time in the system if you opened a second window for taking tickets?
2. You’re working at Boeing after graduation and they have a self serve coffee urn in their employee lunchroom. Arrivals at the urn follow a Poison distribution at the rate of three per minute. In serving themselves, customer take, on average, 15 seconds, exponentially distributed.
How many customers would you expect to see, on average, at the coffee urn?
How long will customers wait in line and to be served”
What percentage of the time is the urn in use?
What is the probability that three people will be at the urn?
3. Trucks arrive at your warehouse at the rate of 15 per hour during business hours. Crews can unload trucks at the rate of 5 trucks per hour. Your employees recently received a significant pay raise due to settling a contract dispute and you’re re-examining the question of how many crews to use. Your new rates are crew and dock cost of $100 per hour and a driver cost of $120 per hour. Determine which number of crews; 4, 5, 6 or 7 will minimize your total cost.