Operations Management Study Set 5

A multiple-channel system assumes that each server will have its own waiting line, and line changing is not permitted.

The cost of customer waiting is easy to estimate, the number waiting multiplied by the wait cost per minute.

The queuing models discussed in the text apply only to steady-state conditions. Steady state exists only when customers arrive at a steady rate; that is, without any variability.

A system has one service facility that can service 10 customers per hour. The customers arrive at a variable rate, which averages six per hour. Since there is excess capacity, no waiting lines will form.

The goal of queuing analysis is to balance the cost of providing a level of service capacity with the possible loss of business due to customers leaving the line or refusing to wait.

According to Little's law, the number of people in line depends on the time of day that they arrive.

To reduce the average number waiting in line, it is important to increase utilization.

An approach to reducing the variability in processing times might include greater standardization.

For a system that has a low utilization ratio, decreasing service capacity slightly will have only negligible effect on customer waiting time.

The most commonly used queuing models assume that the arrival rate can be described by a Poisson distribution.

In a theme park like Disney world, reservation systems are a win-lose situation since only those holding reservations are satisfied.

In an infinite-source model, the average number being served is equal to the ratio of the arrival rate to the service rate.

In an infinite-source model, the system utilization is the ratio of the arrival rate to the service capacity.

All infinite-source queuing models require the system utilization to be less than 1.0.

A single-server, variable-service-time system is known as an M/D/1 system.

A dental office with two professionals (one dentist, one hygienist)who work together as a team would be an example of a multiple-channel system.

The goal of waiting-line management is to eliminate customer waiting lines.

In an infinite-source model, the average time in line is equal to the average number in line divided by the arrival rate.

Waiting lines occur even in underloaded systems because of variability in service rates and/or arrival rates.

The point that minimizes total queuing system costs is that point where waiting costs and capacity costs are equal.