A note on service interruptions

Abstract

This note is devoted to a few remarks on the performance evaluation of systems with service interruptions such as priority queues for lower priority customers, systems subject to breakdowns, etc. Recent work on priority queues has shown that a popular approximation method, the “reduced occupancy approximation”, can be exceedingly inaccurate for a range of parameter values. We identify a cause of inaccuracy and, hence, propose a simple correction that provides a substantial improvement in the results. Using the example of a simple model with service interruptions, we show also that conditional probabilities can be of value in deriving recurrent solutions to some problems.