An optimal multithreshold control for the input flow of the GI/PH/1 queueing system with a BMAP flow of negative customers

A GI/PH/1 queueing system with an additional flow of negative customers is studied. The system has many operation modes differing in the distribution of inter-arrival lengths. Mode control depends on the queue length at arrival instants defined by a multithreshold strategy. The stationary state probability distribution of the system for fixed thresholds is studied. Numerical examples are given to illustrate the determination of the optimal threshold set in a fixed search domain.