Ashish Khemka
Ansys Employee

One should have proper understanding of the design/ the purpose/ the big picture as mentioned by everyone above. For instance many time predicting failure using FEA and inferring the consequences of calculated stresses from a structural finite element analysis can be something of a Pandora's Box. Sometimes the analyst doesn't even know the design details , how it will be tested and assume that the applied loading is applied correctly. There is lot of variability involved - in geometry (tolerances), material properties varies even for a given grade of material and the loading conditions. It is always good to understand how close we are to simulate the need.