The paper deals with deterministic service system with two or three bursts and one servicing device. It is assumed that the service system at any given time serves only one requirement. The goal is the timing of the switching of the service system from one queue to another. In the paper the notion of a cycle of the system services and the concept of steady-state operation of a deterministic service system are suggested. For each of the service systems the necessary and sufficient conditions for steady-state operation are constructed. We also consider two optimization problems for which an optimal solutions are constructed. Discussed problems are similar to the known problem of controlling a traffic light at an isolated intersection. Refs 7. Figs 3