News - Dash Optimization Sponsors Lecture Series at University of Florida

This semester Dash Optimization will be sponsoring a lecture series at University of Florida. The purpose of this lecture series is to expose University of Florida students to a variety of different speakers with industry experience in the Operations Research field. The first speaker in this series is Dr. Laurence Wolsey. Dr. Wolsey will be presenting on February 23, 2006 and will speak about:

Production Planning and Mixed Integer Programming
Laurence A. Wolsey, CORE, Université catholique de Louvain

A wide variety of production planning and supply chain management problems can be formulated as mixed integer programs. Even though the commercial mixed integer programming (MIP) solvers have made remarkable progress in recent years, it still makes a significant difference in terms of solution quality and running time if one uses the "right" formulation for one’s problem.

First we show that a simple mixed integer set, called the mixing set, plays a major role in generating new and tight formulations for a several important production planning problems, in both their un-capacitated and constant capacity versions: the lot-sizing problem with production time windows the stochastic lot-sizing problem with a scenario tree the multi-item problem with a joint set-up cost as well as the lot-sizing problem with varying capacities.

Secondly we discuss an automatic reformulation, cutting plane and heuristics library LS-LIB that allow rapid access to much that is known about tight formulations for production planning problems. Computational results on a couple of industrial cases are presented.