Abstract The product development process is a very challenging one, especially in the case of the automotive industry. The actual constructions require performance and quality while focusing on mechanical performance, lightweight and cost-effective. Thus, the virtual development stage is critical. Once the product is validated according to its geometrical definition and features, it is necessary to evaluate its mechanical performance. This process is usually performed using numerical simulation methods. In this paper, the numerical process performed for the validation of a safety part is discussed. As a specific feature, the assembly is finished using a riveting process. The manufacturing process’s influence on the assembly’s mechanical performance is further investigated. A discussion of the methods available for the design validation summarizes the finding of this specific work.