Recursion models for describing and managing the transient flow of materials in generalized flowlines

This paper describes new algorithms for estimating the transient performance of generalized flowlines in which completed products undergo test and rework until quality standards are met. The recursion approach is extended to incorporate features found in actual systems including (a) small-lot production, (b) priority release of kits, (c) lot sequencing (dispatching) at stations, (d) parallel machines at a station, (e) generalized flowline routing, and (f) test/rework cycles. Accuracy of the modeling approach is investigated and test scenarios demonstrate application of the model as an aid in evaluating certain management policies that affect material flow. A number of tests are based on an actual industrial setting involving the small-lot assembly of circuit cards (i.e., printed circuit boards).