Scheduling a flexible machining system with a dynamic tool movement

A recent trend in flexible machining systems is the growth in systems comprised of several highly versatile machines that produce a wide variety of parts and require a corresponding wide variety of cutting tools. A key distinguishing feature of these systems when compared with systems that have inspired much of the flexible machining system (FMS) scheduling research is dynamic tool movement. The authors focus on the first level of a two-level hierarchical approach for scheduling a multiple resource constrained FMS with dynamic tool movement. They propose a simple, fast, and flexible procedure for generating a job and tool schedule given potentially conflicting objectives that reflect concerns for individual job priorities and efficiencies gained through processing similar jobs together. In particular, the authors consider the objectives of low weighted flow time and low tool movement. The basic mechanics of the procedure, however, are not linked to any specific pair of objectives. The authors tested the procedure, which includes two control parameters for influencing the relative importance of the two objectives, over a set of large problems based on two sources in industry.