Analysis of expected queueing delays for decision making in production planning

Concepts such as Time Based Competition and criticism of traditional cost accounting's role as a basis for decision making in production planning have emphasized the need for operational measures as indicators of manufacturing performance. One such measure is the expected queueing delay at a production facility. In this paper a typical bottleneck work center is considered where semi-manufactured products are processed in batches. The expected queueing delay depends on the batch sizes used at the work center. Emphasis is placed on the derivation of analytical expressions of (bounds on) the minimal expected queueing delay that can be achieved by an optimal batching decision. The analytical expressions can be applied easily to support managerial decisions on reduction of setup time and on expansion of capacity.