Nowadays virtual prototyping has a great impact in the design process of an industrial component. Numerical techniques based on the Finite Element Method (FEM) are mature to provide computational tools that permit complex phenomena to be accurately simulated, even when dealing with multi-physical problems. This work puts in evidence that an inaccurate assessment of the material properties may compromise the benefit of such complex modelling techniques. For this purpose, firstly the case of thermo-mechanically loaded structures will be presented. Considering fire walls for naval applications, the influence of the rock wool elastic modulus in the safety behavior will be emphasized. In the case of steel making component, the paper proofs that only a correct cyclic plasticity model of the material (copper alloy) permits a durability analysis to be accurately performed. Finally, in the case of an energy-harvesting device, the importance of taking into account the orthotropic properties of the material will be highlighted.