Applying tolerance parameters

Describes conditions in which CPLEX applies tolerances.

CPLEX will use the value of the best integer solution found so far, as modified by the tolerance parameters ObjDif (absolute objective function difference) or RelObjDif (relative objective function difference) as the cutoff. Again, it is not typical that users set these parameters, but they are available if you find them useful. Use care in changing these tolerances: if either of them is nonzero, you may miss the optimal solution by as much as that amount. For example, in a model where the true minimum is 100 and the absolute cutoff is set to 5, if a feasible solution of say, 103 is found at some point, the cutoff will discard all nodes with a solution worse than 98, and thus the solution of 100 would be overlooked.