# How do I interpret the CPLEX Optimization Studio MIP gap output?

I'm having difficulties understanding my FlowControl output compared to what the Engine Log shows me.

My output from the FlowControl into the Scripting Log (yellow marks) is cplex.getObjValue(), then cplex.getBestObjValue(), and cplex.getMIPRelativeGap(). The Engine log shows the last entry before the optimization is terminated. I have a dettillim = 15000, which doesn't seem to be reached, but also a few fixed binary variables (LB==UB), so I'm expecting a gap.

Now my question is why (and/or how) does the MIP gap extracted from the FlowControl differ from the last entry in the Engine Log? I can't find any reasonable explanation in the documentation.

• Is it possible that the engine log does not print every single line ? – Kuifje Oct 22 '20 at 12:18