I have stumbled upon a PhD. thesis claiming that the order in which constraints are implemented influences CPLEX performance (for CPLEX 11.00 at least) :
"From observations, the best results are obtained from Cplex when the following are sati ed:
1. Each constraint is fully iterated before the next is considered.
2. The variables are entered into the constraints in the same order that they appear
in the objective function.
3. Dominant coecients for the variables are positioned before smaller coecients
of the same variable in the objective function" (paragraph 4.3.2)
I did play a little bit with my own production planning model and it seems that my CPLEX 12.4 does behave slightly differently depending on the order of constraints in the model. I did not find much on this topic anywhere else so here are my questions :
1) Was this really an issue in CPLEX 11.0 and could it still have an impact on CPLEX 12.4?
2) If the answer is yes, are recommendations above still valid for CPLEX 12.4? Are there any other good practices regarding the order in which constraints are implemented?
Thanks a lot