Server allocation subject to variance constraints

The design of service policies whose aim is to minimize a linear combination of average queue lengths, while keeping their variances below given bounds, is considered in the context of a single-server system with two job types. A family of readily implementable threshold policies which can be used for this purpose is analysed in the steady state. The performance of these policies, as well as their ability to satisfy constraints, is examined numerically and is compared to that of another simple family.