Scheduling manufacturing systems in an agile environment

Producing customized products to respond to changing markets in a short tim e and at a low cost is one of the goals in agile manufacturing. To achieve this goal customized products can be produced using an assembly-driven prod uct differentiation strategy. The successful implementation of this strateg y lies in efficient scheduling of the system. However, little research has been done in addressing the scheduling issues related to assembly-driven pr oduct differentiation strategies in agile manufacturing. In this paper, sch eduling problems associated with the assembly-driven product differentiatio n strategy in a general flexible manufacturing system are defined, formulat ed, and solved. The manufacturing system consists of two stages: machining and assembly. At the machining stage, multiple identical machines produce p arts. These parts are then assembled at the assembly stage to form customiz ed products. The products to be produced in the system are characterized by their assembly sequences that are represented by different digraphs. The s cheduling problem is to determine the sequence of products to be produced i n the system so that the maximum completion time (makespan) is minimized fo r any given number of machines at the machining stage. The scheduling probl ems discussed in this paper have not been solved in the literature. The ori ginality of the paper lies in defining and formulating the problems in the context of agile manufacturing and developing optimal and near-optimal for solving them. The heuristic algorithm solves the scheduling problem in two steps. First, an optimal aggregate schedule is determined by solving a two- machine flowshop problem. Next, the optimal aggregate schedule is decompose d by solving a simple integer programming formulation model. The computatio nal experiment shows that the heuristics provide optimal and near-optimal s olutions to the scheduling problems. (C) 2001 Elsevier Science Ltd. All rig hts reserved.