Scheduling cutting machines in a clothing industry

摘要

In a clothing industry, clothes are produced by assembling fabric cutouts. Fabric rolls on a line, and is cut by automated machines arranged along the line. A fabric cutout f{sub}j, requiring time p{sub}j to be cut, is available for cutting on the first machine at a release date r{sub}j{sup}1, and must be completed, on the same machine, within a deadline D{sub}j{sup}1. On machine M{sub}i, i = 2,..., m, release dates and deadlines related to the cutout are r{sub}j{sup}i = r{sub}j{sup}1 + Δ(i - 1) and D{sub}j{sup}i= D{sub}j{sup}1 + Δ(i -1) respectively, where Δ is a constant factor depending on the speed rate of the fabric. A set-up time occurs on a machine, when switching from one cutout to another. The problem of assigning and scheduling cutting tasks to the minimum number of machines is addressed.