Originally posted by: baohu

I got crazy recently when I input different dat sets into one same mod file the results are very very different.

For dat 1 file the result can be caculated very fast (within 100s) and it is optimal

For dat 2 file the result cannot be obtained via direcrtly executed by Cplex Studio. It can provide a feasible solution when converted to lp file.

I just wonder if this means that my model is not perfect enough???!!!!

I can't say whether your model is correct, let alone "perfect", but it is not terribly surprising for a MIP model to produce substantially different solution times when applied to different data sets.

Originally posted by: baohu

Thanks Paul. I am going to check the data input sets again.