The fuselage assembly process in aerospace engineering is a complex problem that involves the joining of large-scale components, often constructed from compliant materials. Variation simulations of the assembly process is essential to ensure quality of joining. Accurate simulations require solving multiple contact problems representing different assembly situations. For the fuselage assembly through the large-scale and flexibility of the components these contact problems have a large dimension which makes their solution extremely time-consuming. This paper explores the application of domain decomposition methods as a powerful approach to tackle this challenge. By breaking down the fuselage assembly into smaller, manageable subdomains, one can effectively analyze the intricate interactions between components during assembly. The proposed methodology enhances computational efficiency and lower the time for contact problem solving allowing for variation simulations and optimization of assembly process. Through a presented case studies, it is demonstrated how domain decomposition techniques can speed up the simulation of contact problems in fuselage assembly. The findings highlight the features of using different methods in advancing the modeling capabilities within aerospace engineering and their potential to optimize design processes while ensuring compliance with stringent safety standards.