Modeling Fundamentals
No optimal solution - unbounded
- Unlikely. Probably something left out of the model. Remodel and Resolve.
- Introduce reasonable bounds on variables
No feasible solution
- Introduce “fake” variables so that if problem is infeasible some information is returned
- Check formulation for objectives masquerading as constraints
- Use minimal set of infeasible constraints to find error in modeling
Rule of thumb: “do nothing” solution should be feasible