ILOG CPLEX 11.0 User's Manual > Programming Considerations > Tuning Tool > Meet the Tuning Tool > If ILOG CPLEX Finds Solutions But Does Not Prove Optimality

In the case where ILOG CPLEX finds solutions for your model but does not prove optimality in your initial run before invoking the tuning tool, you will likely want to set the time limit per model. See Tuning and Time Limits for more about that idea.

In situations where ILOG CPLEX does not solve your model to optimality for a reason other than a time limit, you should address that reason before you apply the tuning tool.

For example, if your initial run results in an out-of-memory error, consider setting the memory emphasis parameter (MemoryEmphasis (bool), CPX_PARAM_MEMORYEMPHASIS (int)). Then create a file in which you specify a fixed setting of that parameter for the tuning tool to respect. Pass that file to the tuning tool with your model. Fixing Parameters and Tuning Multiple Models in the Interactive Optimizer illustrates this approach.