2147483647

[Louise Ten Harmsen van der Beek]

Dear Everybody,

I am running a program which should return no value for a certain decision variable on an interval from 26 to 36. However, when I run the program, at these numbers it gives the following as outcome: 2147483647. 

The rest seems to work fine. This is when I run the program as an integer linear programming problem. However, then if I want to calculate the LP relaxation of this problem, it gives fractional outcomes for the values 26 to 36 while according to the constraints it still should not give any outcome here. 

Does anybody know how to solve this?

Kind regards,

Louise

[Mohan]

Hello Louise,

Can you share the constraints you added to the model which should make this variable 0 during the interval 26 to 36 ?

[Louise Ten Harmsen van der Beek]

Hi Mohan,

We now added explicit constraints which set a certain interval of variables to 0 by 

 for example NumFinishShifts(w)=0. Yet, now our programs says the following:

Warning: After zero iterations CPLEX 12.7.1 concluded that ObjectiveFunction is infeasible.

our objective function is the following

20*(sum[(p)|12<= ord(p), ord(p)*NumFinishShifts(p)] - sum[(p)|ord(p)<=25, (ord(p) - 1)*NumStartShifts(p)]) - ((20*2)*sum[(p)|2<=ord(p)<=34 , NumStartBreaks(p)])

Thank you!

Kind regards,

Louise

Op donderdag 9 mei 2019 19:55:11 UTC+2 schreef Mohan:

[Mohan]

Hello Louise,

NumFinishShifts(w) = 0 will make NumFinishShifts for all w as 0 unless you added some additional domain conditions.

I suspect some constraints are conflicting with each other causing the infeasibility.

Can you share your project files with data saved as a case file so that I can review it for you ? If you don't want to share it on a public forum, you can reply privately to me or send an email to sup...@aimms.com

Sharing an AIMMS project: https://how-to.aimms.com/Articles/45/45-share-project-files.html