《1992 An integrated model for job-shop planning and scheduling》.pdf

MANAGEMENT SCIENCE Voi, 38 . No, 8. August ]i92 Primed in i.S..1. AN INTEGRATED MODEL FOR JOB-SHOP PLANNING AND SCHEDULING* J. B. LASSERRE LAAS-CNRS, 7 Ayenue du colonel Roche, 31077 Toulouse Cedex, France We consider an integrated job-shop planning and scheduling model . To solve the problem we use a (multi-pass) decomposition approach which alternates between solving a planning problem with a tixed sequence of products on the machines, and a job-shop scheduling problem for a fixed choice of the production plan . The generated production plans atcfeasihlc i.c , there exists at least one feasible schedule to realize that plan. Quality of the solution is investigated and numerical results are presented . {PRODUCTION PLANNING ; JOB-SHOP SCHEDULING ; MIXED INTEGER PROGRAM- MING) 1. Introduction Traditional production planning procedures, e.g., those used in MRP (Material Re- quirement Planning) systems follow a top-down hierarchical approach (see Bitran and Tirupati 1989 for a survey on hierarchical planning) . They start with the generation of specific planned order releases for all final products, subassemblies and component s produced . These order releases are subsequently translated into a set of tasks and due dates, and a detailed job shop scheduling problem is solved to satisfy these due dates . Since the produclion planning proc