Originally posted by: anahana

Hello everyone, 

I am starting a large research project on oil refinery scheduling operations and was wondering which optimization tool is suitable. In particular, I have the following options: IBM ILOG CP 1.7 which contains scheduler and solver, and CPLEX Optimization studio which contains CPLEX and CP Optimizer.

I have two questions:

1. Is scheduler in IBM ILOC CP 1.7 different from CP Optimizer in the optimization studio? If so, how? 

2. Assuming I want to use both mathematical programming (through CPLEX) and constrain programming (through CP), can I call libraries from both in the same project? I will be using C++ under MSVS 2012.

Thank you. 

Originally posted by: PhilippeLaborie

Hello,

1. Yes, the scheduling model in IBM ILOG CPLEX Optimization Studio is different from the one in IBM ILOG CP 1.7 (ILOG Scheduler). The modeling language for scheduling was completely redesigned. In CPLEX Optimization Studio, the scheduling language is now much cleaner from a Constrained Optimization perspective (with clearly identified decision variables and constraints) and, for most of the use-cases, more expressive. Furthermore, CPLEX Optimization Studio provides a powerful automatic search for scheduling models so that the usual way to use it is through a Model&Run paradigm where, just like for CPLEX, you focus on designing a model that can be solved efficiently by the automatic search (but it is still possible, just like in ILOG Scheduler to define your own custom constraint and search in C++ if it is really needed). If you want to have an idea of how several scheduling concepts are modeled in CP Optimizer, a good entry point is the section "Designing scheduling models" of the CP Optimizer User's Manual.

2. Sure, you can call both CPLEX and CP Optimizer in the same project. This is even a very usual way to use CPLEX Optimization Studio for solving complex scheduling problems.

Philippe

Originally posted by: anahana

Thanks Philippe. I'll start using CP Optimizer then :)