Operation of pipeless batch plants – II. Vessel dispatch rules

Abstract

Pipeless batch plant operation using schedules generated by an MILP is analyzed in Part I of this paper. In this part the results of the MILP are compared to the results obtained by using local dispatch rules to govern station operation and vessel movement. These local dispatch rules are developed using general notions of efficient performance of flexible manufacturing systems combined with specific observations of the MILP solutions. It is found that the dispatch rules perform quite poorly when based on general principles, but can achieve almost indistinguishable performance compared to the MILP, when the features of the MILP schedule are incorporated into the rules. It is found that the rules are sensitive to the particular layout structure of the plant, and that customized rules for a layout can be obtained