Some Queuing Problems with the Service Station Subject to Breakdown

A number of situations is considered where the single service station is incapacitated from time to time to render service to the incoming stationary Poisson stream of customers. Five models are presented Model. A deals with the situation in which the service interruption is brought about by a Poisson process homogeneous in time. The preemptive priority queuing model is shown to be a special case. Model B is concerned with the case in which breakdowns occur only while the station is giving service. In Model C it is assumed that the repair process cannot start without customers at the station. Model D describes a situation in which the repair of the station starts at the initiative of a customer who wishes to improve the standard of service. In Model E the assumption is that the station can break down only while no customer is being serviced. In all models it is assumed that service times and repair times possess arbitrary distribution functions each having a density and finite second moment. The expected queue lengths and related operating characteristics of the various systems are derived using relatively simple mathematical methods.