Title: Simultaneous lot-sizing and scheduling problem in flow shop environment with outsourcing

Authors: Mohammad Saleh Fadaki; Mehdi Bijari

Addresses: Department of Industrial and Systems Engineering, Isfahan University of Technology, Isfahan 84156-8311, Iran ' Department of Industrial and Systems Engineering, Isfahan University of Technology, Isfahan 84156-8311, Iran

Abstract: Lot-sizing and scheduling are two important issues in production planning problems. This study considers the simultaneous lot-sizing and scheduling problem in a capacitated flow shop environment with outsourcing. We propose a new exact formulation for the simultaneous lot-sizing and scheduling problem in a flow shop environment with sequence dependent setups as a mixed integer program. For demonstrating the efficiency of the proposed model, we compare it with a former model pertaining to a flow shop environment. The proposed model's efficiency is better than the former model because the number of continuous and binary variables, the number of constraints, and the solving CPU time are less than the former model. Since finding the exact solution for medium- and large-size instances is impossible within a reasonable time due to the complexity of the problem, four MIP-based rolling horizon heuristics are provided. The computational results show the effectiveness of heuristic algorithms.

Keywords: lot sizing; flowshop scheduling; sequence-dependent setup times; outsourcing; MIP-based heuristics; mixed integer programming; rolling horizon; production planning; capacitated flow shops.

DOI: 10.1504/IJPS.2016.080345

International Journal of Planning and Scheduling, 2016 Vol.2 No.3, pp.252 - 271

Received: 15 Oct 2015
Accepted: 13 Sep 2016
Published online: 15 Nov 2016 *

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