Op 15-11-12 14:26, oliver.rolle schreef: Interesting. Simplex will give only give you the optimal solution if you have enough time to let it run that long. For medium/large cases with a real number of constraints, this can easily be years. In practice, it is never about finding the optimal solution, it's about finding the best solution in a fixed amount of time. No. Planner doesn't force you to use only linear constraints. In the experiments and competitions I 've been involved with [1], I 've seen the following: - Simplex is better at scaling down (< 100 variables, < 100 values) - Drools Planner is far better at scaling up (> 10 000 variables, > 10 000 values) (Simplex goes out of memory) - In the range between, they average out. - Drools Planner can do real-time planning: good solutions in ms after the last problem change. [1] Google Roadef 2012, ITC 2007, INRC 2010, ...