ILOG CPLEX 11.0 User's Manual > Infeasibility and Unboundedness > Diagnosing Infeasibility by Refining Conflicts > What a Conflict Is Not

Information about the necessary magnitude of change to data values, in order to gain feasibility, is not available from a conflict. The algorithms for detecting and refining conflicts do their work by including or removing a constraint or bound in trial solutions, not by varying the data of those entities. For that kind of insight, or for an approach to automatic repair of infeasibility, the FeasOpt feature, discussed in Repairing Infeasibilities with FeasOpt, is more appropriate.

ILOG CPLEX refines conflicts only among the constraints and bounds in your model. It disregards the objective function while it is refining a conflict. In particular, if you have set a MIP cutoff value with the idea that the cutoff value will render your model infeasible, and then you apply the conflict refiner, you will not achieve the effect you expect. In such a case, you should add one or more explicit constraints to enforce the restriction you have in mind. In other words, add constraints rather than attempt to enforce a restriction through these parameters: