Originally posted by: nicolasdebray

Hello,

I am currently trying to find an optimal solution for a rectangle packing by implementing my model with flow control and using a MIP start in excel but it always gives back the same running error after a while (it has now been running for 7 hours in a row). The thing is that it stays blocked at root node 0 I think. 

Basically, I have to pack as much firms as possible in a defined rectangle to maximize a revenue. (with a beginning set of 400 firms).

Does anyone have any idea on how I could correct this in order to run it correctly? I thought about iteratively constraining the max number of firms (represented by small rectangles) allowed in the given rectangle to get a first solution and then the program would iteratively use this solution to get to an optimal but I can't actually write this constraint down. As it apparently doesn't work that well with excel I also tried to get the solutions written back to an .mst file but I can't get it running. (I zipped the mst file)

Thank you in advance for any help,

Regards,

Nicolas

Hi,

you could get some ideas at https://www.ibm.com/developerworks/community/forums/html/topic?id=72359501-c169-4215-9dc0-1c87e653b584&ps=25

There you have an example on how to hybrid CPO and CPLEX and warmstart from one to the other

regards