Generalisation of unidirectional loop layout problem and solution by a genetic algorithm

ÖZÇELİK F., Islier A. A.

INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH, vol.49, no.3, pp.747-764, 2011 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 49 Issue: 3
  • Publication Date: 2011
  • Doi Number: 10.1080/00207540903496673
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.747-764
  • Keywords: unidirectional loop layout problem, loading, unloading station, location-allocation problem, genetic algorithm, FLEXIBLE MANUFACTURING SYSTEMS, NETWORK LAYOUT, CONVEYOR SYSTEM, MACHINE LAYOUT, DESIGN PROBLEM, HEURISTICS, STATIONS, MODEL
  • Eskisehir Osmangazi University Affiliated: Yes


Unidirectional loop layouts (ULLs) are the preferred layouts in manufacturing systems owing to their relative low investment costs, high material handling elasticity and routing flexibility. Existing formulations of the unidirectional loop layout problem are concentrated on the arrangement of workstations under the assumption that the number and location of loading and unloading stations are known. In this study, the unidirectional loop layout problem is generalised by consideration of potentially attachable loading/unloading equipment to each workstation and releasing of the predetermined number of loading and unloading stations. Thus, more efficient and effective loop layout designs are allowed by eliminating some artificial restrictions. The present ULL model is generalised and a genetic algorithm is developed to solve the problem. Solutions obtained by the genetic algorithm outperformed those obtained by conventional methods. Additionally, comparisons of the generalised model with existing models on randomly generated test problems yielded encouraging results.