• Title/Summary/Keyword: Two-machine Flowshop

Search Result 13, Processing Time 0.017 seconds

Production Scheduling for a Flexible Manufacturing Cell

  • 최정상
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
    • /
    • 1998.03a
    • /
    • pp.209-213
    • /
    • 1998
  • This study considers flowshop scheduling problem related to flexible maufacturing cell in which consists of two machining centers, robots for loading/unloading, and an automated guided vehicle(AGV) for material handling between two machining centers. Because no machinng center has buffer storage for work in process, a machining center can not release a finished job until the empty AGV is available at that machining center. While the AGV cannot tranfer an unfinished job to a machining center until the machining center empty. In this paper, an new heuristic algorithm is given to find the sequence that minimize their makespan.

  • PDF

A Development of Optimal Algorithms for N/M/D/F/Fmax Scheduling Problems (N/M/D/F/Fmax 일정계획 문제에서 최적 알고리듬의 개발)

  • 최성운
    • Journal of Korean Society of Industrial and Systems Engineering
    • /
    • v.13 no.21
    • /
    • pp.91-100
    • /
    • 1990
  • This paper is concerned with the development of optimal algorithms for multi-stage flowshop scheduling problems with sequence dependent setup times. In the previous researches the setup time of a job is considered to be able to begin at the earliest opportunity given a particular sequence at the start of operations. In this paper the setup time of a job is considered to be able to begin only at the completion of that job on the previous machine to reflect the effects of the setup time to the performance measure of sequence dependent setup time flowshop scheduling. The results of the study consist of two areas; first, a general integer programming(IP) model is formulated and a nixed integer linear programming(MILP) model is also formulated by introducing a new binary variable. Second a depth-first branch and bound algorithm is developed. To reduce the computational burdens we use the best heuristic schedule developed by Choi(1989) as the first trial. The experiments for developed algorithm are designed for a 4$\times$3$\times$3 factorial design with 360 observations. The experimental factors are PS(ratio of processing time to setup time), M(number of machines), N(number of jobs).

  • PDF

On optimal cyclic scheduling for a flexible manufacturing cell

  • Kise, Hiroshi;Nakamura, Shinji;Karuno, Yoshiyuki
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1990.10b
    • /
    • pp.1250-1255
    • /
    • 1990
  • This paper discusses an optimal cyclic scheduling problem for a FMC (Flexible Manufacturing Cell) modeled by a two-machine flowshop with two machining centers with APC's (Automated Pallet Changers), an AGV (Automated Guided Vehicle) and loading and unloading stations. Cyclic production in which similar patterns of production is repeated can significantly reduce the production lead-time and WIP (Work-In-Process) in such flexible, automated system. Thus we want to find an optimal cyclic schedule that minimizes the cycle time in each cycle. However, the existence of APC's as buffer storage for WIP makes the problem intractable (i.e., NP-complete). We propose an practical approximation algorithm that minimizes, instead of each cycle time, its upper bound. Performances of this algorithm are validated by the way of computer simulations.

  • PDF