Safia Kedad-Sidhoum

A multi-stage stochastic integer programming approach for a multi-echelon lot-sizing problem with returns and lost sales

  • Quan Dong
  • Safia Kedad-Sidhoum
  • Céline Gicquel
  • Franco Quezada
    • Categories Applications - OR and Management Sciences, Branch and Cut Algorithms, Production and Logistics Tags , , , , , ,

    We consider an uncapacitated multi-item multi-echelon lot-sizing problem within a remanufacturing system involving three production echelons: disassembly, refurbishing and reassembly. We seek to plan the production activities on this system over a multi-period horizon. We consider a stochastic environment, in which the input data of the optimization problem are subject to uncertainty. We propose a … Read more

    Coordination of a two-level supply chain with contracts

  • Safia Kedad-Sidhoum
  • Fanny Pascual
  • Siao-Leu Phouratsamay
    • Categories Dynamic Programming, Production and Logistics, Supply Chain Management Tags , , , ,

    We consider the coordination of planning decisions of a single product in a supply chain composed of one supplier and one retailer, by using contracts. We assume that the retailer has the market power: he can impose his optimal replenishment plan to the supplier. Our aim is to minimize the supplier’s cost without increasing the … Read more

    Coordination of a two-level supply chain with contracts under complete or asymmetric information

  • Safia Kedad-Sidhoum
  • Fanny Pascual
  • Siao-Leu Phouratsamay
    • Categories Dynamic Programming, Supply Chain Management Tags , , , , ,

    We consider the coordination of planning decisions of a single product in a supply chain composed of one supplier and one retailer by using contracts. We assume that the retailer has the market power to impose his optimal replenishment plan to the supplier. Our concern is on the minimization of the supplier’s cost. In order … Read more

    Single-Machine Common Due Date Total Earliness/Tardiness Scheduling with Machine Unavailability

  • Kerem Bülbül
  • Safia Kedad-Sidhoum
  • Halil Sen
    • Categories Scheduling

    Research on non-regular performance measures is at best scarce in the deterministic machine scheduling literature with machine unavailability constraints. Moreover, almost all existing works in this area assume either that processing on jobs interrupted by an interval of machine unavailability may be resumed without any additional setup/processing or that all prior processing is lost. In … Read more

    Conic relaxation approaches for equal deployment problems

  • Safia Kedad-Sidhoum
  • Tim J. Mullin
  • Satoko Moriguchi
  • Makoto Yamashita
    • Categories (Mixed) Integer Nonlinear Programming, Linear, Cone and Semidefinite Programming

    An important problem in the breeding of livestock, crops, and forest trees is the optimum of selection of genotypes that maximizes genetic gain. The key constraint in the optimal selection is a convex quadratic constraint that ensures genetic diversity, therefore, the optimal selection can be cast as a second-order cone programming (SOCP) problem. Yamashita et … Read more

    Fast Neighborhood Search For The Single Machine Earliness-Tardiness Scheduling Problem

  • Safia Kedad-Sidhoum
  • Francis Sourd
    • Categories Scheduling Tags , , ,

    This paper addresses the one machine scheduling problem in which $n$ jobs have distinct due dates with earliness and tardiness costs. Fast neighborhoods are proposed for the problem. They are based on a block representation of the schedule and can be computed in $O(n^2)$. A timing operator is presented as well as swap and extract-and-reinsert … Read more

    An exact algorithm for solving the ring star problem

  • Safia Kedad-Sidhoum
  • Viet Hung Nguyen
    • Categories Branch and Cut Algorithms, Network Optimization, Telecommunications Tags , , , ,

    This paper deals with the ring star problem that consists in designing a ring that pass through a central depot, and then assigning each non visited customer to a node of the ring. The objective is to minimize the total routing and assignment costs. A new chain based formulation is proposed. Valid inequalities are proposed … Read more

    MIP-based heuristics for multi-item capacitated lot-sizing problem with setup times and shortage costs

  • Nabil Absi
  • Safia Kedad-Sidhoum
    • Categories Applications - OR and Management Sciences Tags , , , , , ,

    We address a multi-item capacitated lot-sizing problem with setup times that arises in real-world production planning contexts. Demand cannot be backlogged, but can be totally or partially lost. Safety stock is an objective to reach rather than an industrial constraint to respect. The problem is NP-hard. A mixed integer mathematical formulation is presented. We propose … Read more

    The multi-item capacitated lot-sizing problem with setup times and shortage costs

  • Nabil Absi
  • Safia Kedad-Sidhoum
    • Categories Branch and Cut Algorithms, Production and Logistics Tags , , , , , ,

    We address a multi-item capacitated lot-sizing problem with setup times and shortage costs that arises in real-world production planning problems. Demand cannot be backlogged, but can be totally or partially lost. The problem is NP-hard. A mixed integer mathematical formulation is presented. Our approach in this paper is to propose some classes of valid inequalities … Read more

    An efficient algorithm for the earliness-tardiness scheduling problem

  • Safia Kedad-Sidhoum
  • Francis Sourd
    • Categories Scheduling Tags

    This paper addresses the one-machine scheduling problem with earliness-tardiness penalties. We propose a new branch-and-bound algorithm that can solve instances with up to 50 jobs and that can solve problems with even more general non-convex cost functions. The algorithm is based on the combination of a Lagrangean relaxation of resource constraints and new dominance rules. … Read more