This thesis presents the development of a Femap custom post-processing tool for the assessment of composite laminate initial failure and sandwich structure Margins of Safety (MOSs) in aerospace applications, developed in collaboration with Thales Alenia Space. The developed program aims at automating the evaluation of the main structural MOSs, significantly reducing analysis time and minimizing the risk of human error associated with manual post-processing activities. At the same time, the tool promotes the adoption of advanced failure theories for composite laminates in industrial finite element analyses. A graphical user interface was developed in order to provide a practical and user-friendly software for structural analysts.