Chapter 11 – Queueing Models
1. The goal of queuing analysis is to minimize customer waiting lines.
2. Queueing models enable finding an appropriate balance between the cost of service and the
amount of waiting.
3. The cost of customer waiting is easy to estimate.
4. Most queueing models assume that the form of the probability distribution of interarrival
times is an exponential distribution.
5. The only distribution of interarrival times that fits having random arrivals is the exponential
distribution.
6. The lack-of-memory property refers to a customer’s willingness to wait in line even though
there are other customers that will be served first.
Chapter 11 – Queueing Models
11–11
Customers filter into a record shop at an average of 1 per minute (exponential interarrivals)
where the service rate is 15 per hour (exponential service times).
54. What is the average number of customers in the system with 8 servers?
55. What is the minimum number of servers needed to keep the average time in the system
under 6 minutes?
56. What is the system utilization factor if 5 servers are used?
Customers arrive at a video rental desk at the rate of one per minute (exponential interarrival
times). Each server can handle 0.4 customers per minute (exponential service times).
