If the Solver stops with a solution (set of values for the decision variables or changing cells) which is different from what you expect, or what you believe is correct, follow the suggestions outlined on this page. You can usually narrow down the problem to one of a few possibilities.
- Read the message in the Solver Results dialog. This is crucial to diagnosing the problem. You can learn a good deal about each possible message by clicking the link above.
- Consider carefully the possibility that the solution found by the Solver is correct, and that your expectation is wrong. This may mean that what your model actually says is different from what you intended.
- Check the Show Iteration Results box in the Solver Options dialog and re-solve. The Solver will pause with the message "Solver paused, current solution values displayed on worksheet." Click Continue to see the path towards the solution taken by the Solver.
After you take these steps, follow the links below for more information on common misunderstandings that can lead to unexpected or "wrong" solutions:
- Problems with Poorly Scaled Models
- Tolerance Option for Integer Problems
- Limitations of Nonlinear Optimization
- GRG Nonlinear Solver Stopping Conditions
- Problems with Nonsmooth and Discontinuous Functions