Extensions to class dominance characteristics

Balachandran and Schaefer show that if in the individual optimum class A dominates with a first come first serve queue, there could exist cases where in the public optimum class B dominates. The authors derive conditions under which providing a nonpreemptive priority allows both classes of users to use the facility and get a higher expected public net benefit than the first come first serve queue. The class that is provided the higher priority may or may not be the class that dominates in the public optimum under the first come first serve queue. That means that introducing a priority scheme may switch the class that is given preference in the public optimum. It is shown that there exist situations where the class that is granted the higher priority for service could be levied a lower price than the class that is granted the lower priority. In the case where the users alone have perfect information on the value from using the facility, the authors derive conditions under which a non preemptive priority is superior to the first come first serve queue. The preemptive priority resume queue is not necessarily always superior to the first come first serve queue. The authors derive conditions under which the superiority of the preemptive priority resume queue over the first come first serve queue holds.