The presented work is a step towards designing a numerical strategy capable of assessing the nocivity of a small defect in terms of its size and position in the structure with low computational cost, using only a mesh of the defect-free reference structure. The proposed strategy would allow to assess the criticality of defects by introducing trial micro-defects with varying positions, sizes and me- chanical properties. The main focus of the this work is to present two computational scenarios allowing to efficiently evaluate criticality considering the effect of either a fixed flaw on a region of interest or varying flaws on a fixed evaluation point.