Archives for September 2014

Using the CPLEX tuning tool on difficult models

The question on how a tuning tool can help solve difficult optimization models has been intriguing to me. For those new to the concept, the tuning tool tries different parameter settings and seeks to find good parameters for the solver for a given optimization model. The use of this tool is rather straightforward on easy models, […]

OR-Enabled Collaborative Logistics

Today’s post is about collaborative logistics, one field of study in which I recently started to work in. It is a tricky field for many reasons, and I will try to explain why and how. Operations research is a key enabler of collaboration. Logistics is essentially management of the activities of transporting and holding materials from origins […]

Seeds and parallel MIP solvers, extended edition

In a previous post, I showed that changing the random seed on a given problem yielded varies solution times by between 20% to 40% on average, depending on the solver and the setting. I decided to push that experiment a little further and sample the distribution of run times based on the variation in random seeds. […]