PRINCIPLES OF MODELLING 1
1. Do not build a complicated model when a simple one will suffice.
This can be contrary to traditional mathematics or when one wants to build a general, strong model. Typically, though, a useful model is a simple model.
2. Beware of molding the problem to fit the technique.
This happens often if somebody is an "expert" in a specific solution technique. However, optimization is just one of many decision support techniques.
3. The deduction phase of modeling must be conducted rigorously.
If you do this and the conclusions are inconsistent with reality, then the fault lies in the assumptions.
Be extremely careful with computer programs which may contain hidden bugs.