Maximizing throughput in zero-buffer tandem lines with dedicated and flexible servers

For tandem queues with no buffer spaces and both dedicated and flexible servers, this article studies how flexible servers should be assigned to maximize the throughput. The optimal policy is completely characterized. Insights gained from applying the Policy Iteration algorithm to systems with three, four, and five stations are used to devise heuristics for systems of arbitrary size. These heuristics are verified by numerical analysis. Throughput improvement obtained when, for a given server assignment, dedicated servers are changed to flexible servers.