10h30 - 10h55
Stochastic optimization for material requirement planning (MRP) under demand uncertainty
We investigate multiple stochastic optimization formulations for Master Requirement Planning systems under stochastic demand. The execution of the resulting methods is simulated in three environments, which differ by the decisions updated at each period. Results show that these methods lead to signiﬁcantly lower costs than classical approaches.
10h55 - 11h20
A branch-and-cut algorithm for an assembly routing problem
We consider an integrated optimization problem including the production, inventory and inbound transportation decisions where several suppliers each provide a subset of components necessary for the production of a final product. We present several classes of valid inequalities for this problem. Computational experiments show the performance of our branch-and-cut algorithm.
11h20 - 11h45
Two-level capacitated facility location with concave costs
We study a two-level capacitated facility location problem with concave costs for production,inventory and transportation. The concave costs assumption represents economies of scale,and hence the resulting problem is an integer concave minimization problem. We compute lower and upper bounds to this problem using Lagrangian relaxation and inner integer approximations.
11h45 - 12h10
Lot-sizing models with simultaneous backlogging and lost sales
We study capacitated multi-item lot-sizing models which simultaneously consider the possibility of backlog and lost sales as a means of dealing with a stock-out. We propose new formulations considering several types of interactions between these two types of recourse and by allowing that customers have a different willingness to wait.