Heuristic lot size scheduling on unrelated parallel machines with applications in the textile industry

Abstract

In this paper, we present an industrial problem found in a company that produces acrylic fibres to be used by the textile industry. The problem is a particular case of the discrete lot sizing and scheduling problem (DLSP). In this problem, lots of similar products must be generated and sequenced in ten unrelated parallel machines, in order to minimize tool changeovers and the quantity of fibre delivered after the required due date. The company problem is original because a changeover can occur between two lots of the same product due to tool wear. We analyse the problem in detail and present an adaptation of a heuristic found in the literature to solve it. Results obtained with the proposed heuristic are compared with results that used to be obtained by the production planner, using historical data. q

Iterated hybrid metaheuristic algorithms for unrelated parallel machines problem with unequal ready times and sequence-dependent setup times

“…4. Assume a solution in which the job sequence on machine 1 (M1) is (1,3,5) and the job sequence on machine 2 (M2) is (2,4). The four neighborhood structures used in the proposed IVT are illustrated as follows.…”

“…Unrelated parallel machine scheduling problems show up in real-world applications, such as PCB fabrication drilling operations [1,2], semiconductor wafer manufacturing dicing [3], the spinning of acrylic fibers for production in the textile industry [4], chip attach operations in the back-end semiconductor assembly line [5], and scheduling jobs in a printed wiring board (PWB) manufacturing environment [6].…”

Multi-product lot sizing and scheduling on unrelated parallel machines

“…Other applications of this model can be found in metal production in foundries (dos Santos-Meza, dos Santos and Arenales [2], and de Araujo, Arenales and Clark [1]), and textile industry (Silva and Magalhaes [18], and Taner et al [22]). In these large-scale problems, the efficient utilization of the critical production units constitutes the main source of complexity.…”

An evaluation of semidefinite programming based approaches for discrete lot-sizing problems

“…Sequence-dependent changeover costs and times are mentioned in [18] as one of the relevant operational aspects to be incorporated into lot-sizing models. Moreover, a significant number of real-life lot-sizing problems involving sequence-dependent changeover costs and times have been recently reported in the academic literature: see among others [5] for an injection moulding process, [29] for a textile fibre industry or [8] for soft drink production. A wide variety of solution techniques from the Operations Research field have been proposed to solve lot-sizing problems: the reader is referred to [4,17] for recent reviews on the corresponding literature.…”