Questions from Management Science

Q: A laundromat has five washing machines. A typical machine breaks down

A laundromat has five washing machines. A typical machine breaks down once every five days. A repairman can repair a machine in an average of 2.5 days. Currently, three repairmen are on duty. The owne...

Q: The limited source model can often be used to approximate the behavior

The limited source model can often be used to approximate the behavior of a computer’s CPU (central processing unit). Suppose that 20 terminals (assumed to always be busy) feed the CPU. After the CPU...

Q: Consider an airport where taxis and customers arrive (exponential interarrival times

Consider an airport where taxis and customers arrive (exponential interarrival times) with respective rates of one and two per minute. No matter how many other taxis are present, a taxi will wait. If...

Q: A bank is trying to determine which of two machines to rent

A bank is trying to determine which of two machines to rent for check processing. Machine 1 rents for $10,000 per year and processes 1000 checks per hour. Machine 2 rents for $15,000 per year and proc...

Q: You can easily generate random numbers in a spreadsheet that have an

You can easily generate random numbers in a spreadsheet that have an exponential distribution with a given mean. For example, to generate 200 such numbers from an exponential distribution with  = 1...

Q: A worker at the State Unemployment Office is responsible for processing a

A worker at the State Unemployment Office is responsible for processing a company’s forms when it opens for business. The worker can process an average of four forms per week. Last year, an average of...

Q: A manufacturing company makes two products. Each product can be made

A manufacturing company makes two products. Each product can be made on either of two machines. The time (in hours) required to make each product on each machine is listed in the file. Each month, 500...

Q: For the M/M/1 queueing model, why do

For the M/M/1 queueing model, why do the following results hold? a. W = (L + 1) /  b. WQ = L /

Q: Referring to Problem 18, suppose the airline wants to determine how

Referring to Problem 18, suppose the airline wants to determine how many checkpoints to operate to minimize operating costs and delay costs over a 10-year period. Assume that the cost of delaying a pa...

Q: The manager of a bank wants to use an M/M

The manager of a bank wants to use an M/M/s queueing model to weigh the costs of extra tellers against the cost of having customers wait in line. The arrival rate is 60 customers per hour, and the ave...