Management Science vol:44 issue:11 - Part I pages:1548-1561
A general hierarchical procedure is proposed to address real-life job shop scheduling problems. The shop typically produces a variety of products, each with its own arrival stream, its own route through the shop and a given customer due date. The objective is to minimize the expected lead time, and therefore the production environment is modeled as a queuing network. Given these lead times, release dates are set dynamically. This in turn creates a time window for every manufacturing order in which the various operations have to be sequenced. The sequencing logic is based on an extended shifting bottleneck procedure. These three major decisions are next incorporated into a four-phase, hierarchical, operational implementation scheme. A small numerical example is used to illustrate the methodology. The final objective, however, is to develop a procedure that is useful for large, real-life, shops.