Archives for April 2013

Speedups: comparing against moving targets

[This is post #1 of 2 that were inspired by a tweet from IBM’s Jean-François Puget] Over the course of my studies, I had to develop custom solution methods for very challenging supply chain network design problems. While striving to create better models and solution algorithms, I had to compare the performance of my approach […]

Deterministic behavior of CPLEX: ticks or seconds?

If you are a longtime user of CPLEX, you probably noticed the addition of a number of “ticks” in addition to the displayed wall clock time count in recent versions. According to IBM, it’s a computer-independent measure of how much algorithmic work is required to obtain a provable optimum, independently of the computer on which […]

Tools for teaching Optimization in Business School

Using Operations Research (OR) in the classroom is important to me. I do not teach optimization theory classes, but mostly supply chain, operations management and production planning & control. My students do not learn optimization basics in my class. However, at the beginning of the course, their optimization experience is often limited to a small […]

Can the CPLEX tuning tool help solving hard models?

The CPLEX MIP Solver has had a tuning tool for some time. 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. I have tested the tuning tool on 10 relatively difficult-to-solve models. By difficult, I mean models […]