Size optimization of mechanical parts can be very complex and can hardly describe in words. This is due to the stress concentrations and component interaction need to be taken into account. This is therefore the use of hybrid intelligent systems for size optimization of mechanical parts under cyclic loadings are needed to be investigated. Different types of modern methods for optimization were studied as well as cases of optimization using different finite element method software. In this final year project, the objective function, mass was optimized by considering both static and dynamic loadings.