Finite Element Analysis is a stress analysis technique where the structure in question is subdivided in many smaller parts, appropriate restrains are applied and then the structure is subjected to forces or loads.
The results are then analysed in great detail with regards to resultant forces orientation and ply-by-ply failure analysis. This leads to deep understanding of the structure and creates the steps towards optimisation of it.
Fibre type can vary depending on location of the component, optimal fibre orientation can provide reduced weight and increased material properties. Resin selection can be optimised to achieve toughness or high temperature demands or just plain cost savings.