How problematic are your Big M constraints? an experiment [primal]

This post investigates whether it is still relevant to be careful about the coefficients used in so-called Big M constraints when formulating mixed-integer programming (MIP) models. I make some experiments with two-echelon supply chain design models to show that using too large values often cause the models to be harder to solve. The impact is much greater […]

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. […]

Using commercial solvers in academic research

Over the last two years or so, I’ve ran into a couple of discussions about the use of commercial solvers in academic OR projects. There is often a moderate sense of unease when using commercial MILP solvers in our research. The problem is not the commercial property of the software – at least, not since […]