The recommendation game [dual]

People who teach or supervise students have a tremendous influence on what solvers get adopted by the community. Once they finish their studies, many students will continue to use the tools they have learned in school; it is simply more efficient. In this post, I explain the reasons behind the choice of tools I use in class. […]

The recommendation game [primal]

People who teach or supervise students have a tremendous influence on what solvers get adopted by the operations research / industrial engineering community. Once they finish their studies, many students will continue to use the tools they have learned in school, for many reasons. First, it is simply the most efficient strategy to adopt. Also, […]

It’s time talk more about barrier in class

In today’s post, I argue that optimization classes and textbooks should put a greater emphasis on interior point methods. During my many years of study, I have been exposed to quite a bit of simplex theory. I also had to perform many primal and dual simplex pivots by hand, as it was considered a good […]

Just a LP, really?

In recent talks in scientific conferences, I saw some people dissmiss pure linear programming (LP) models as being easy and primitive. I often got said “oh, that’s just a LP”. Linear programming is put in the box of solved problems, like some network problems such as the (pure) shortest path or max flow. In fact, I think […]

Exam design problem

For students, the final exam week is probably the most stressful time of a semester. They often have multiple exams over consecutive days and need to split their last-minute study and preparation time over these topics. I must confess that I also feel some stress during this week. Here’s why. First, designing an exam is not so […]

Inventory routing when it matters

Yesterday we had the pleasure of welcoming Prof. Leandro C. Coelho for a research seminar at the Forac research consortium. He presented his work on the inventory routing problem (IRP) which is a combination between the vehicle routing problem (VRP) and inventory management problems. Leandro is a very prolific writer, with many research contributions on […]

Academia and software neutrality

When I started my PhD, the only MIP solver that was used at the lab was Cplex. At that time, it was considered the best by the people I worked with. I say “considered”, because I took this assumption as a fact without actually testing it. I could have been working with the wrong solver without […]

ILS 2014, a buffet of logistics and OR

This post was originally written for OR Complete. I re-post it here in case you missed the original posting. ILS – a short name for the International Conference on Information Systems, Logistics and Supply Chain, is a bi-annual conference focusing on global supply chain and logistics management, with a focus on information systems and decision support systems. […]

Uncertainty, Models, and the Chaos Out There

Future is dominated by uncertainty. In terms of supply chain management – my main field of application – it comes in terms of variation in lead times or demand levels, or in the form of severe events such as hurricanes which can severely disrupt a supply chain. Optimization can help to cope with uncertainty, but I […]

Things you learn in a Ph.D. that are not written in textbooks

Those are things I learned during the first phase of my experimentation over the course of my Ph.D (year 2 of 4) There is a story behind each of this statements; I may blog about some of them if there is interest in it and I find the time to write that. Please note that some of […]