Originally posted by: MFC

Hi, 

I have a question about setting the optimization parameters such as FailLimit, TimeLimit, or OptimalityTolerance while using staticLex (multi objective) functionality. Let's say  we have two objectives staticLex(obj1, obj2). How can we control parameters for first and second objectives? When we set lets say FailLimit=1000, will it effect the first objective or is it also applied to the second objective?

Thanks a lot in advance. 

Originally posted by: PhilippeLaborie

Hello,

Limits and tolerances apply to the search globally, even when you are using staticLex as objective in the model. If you want to have a more control on the resolution of multi-objective problems, you can solve the problem in several steps, each step focusing on some part of the objective. For doing that you may consider using the warmstart functionality of CP Optimizer. With warmstart, you can start the search from a previously known solution. See the example sched_goalprog in the delivery of CP Optimizer.

Philippe

Originally posted by: davidoff

Hello

I'm continuing this question since it is very interesting from a user prospective to use static Lex directly instead of writing a more complex scheme as Philippe suggests.

In other frameworks, you can simply set time (or other criterion) limits for the first objective , and an other one for the second.

If the optimality of the first criterion is not proven, will CPO takes all the available time to improve it regardless of the second criterion ?

Thanks

David

Originally posted by: davidoff

Well apparently the other related post

https://www.ibm.com/developerworks/community/forums/html/topic?id=77777777-0000-0000-0000-000014927470&ps=25

explains that staticLex is not a 2 step optimization scheme.