Plate and shell formulations by the boundary element method can be used to analyze thin-walled space structures. These structures, built by assembling the plate in the space, allow the modeling of structures commonly found in aeronautical, aerospace, naval, and oceanic applications. In this chapter, we present a methodology for the boundary element analysis of thin-walled spatial structures by assembling the discretized boundary equations of their constituent elements. These equations are obtained from the methodologies presented in previous chapters. These equations are coupled mathematically from conditions of continuity of displacements and rotations and equilibrium of forces and moments in contours and coupling surface between the plates. By means of application examples, the methodology is applied to the analysis of thin-walled structures. As a special case and of relevance to the aircraft industry, the application of the methodology to the analysis of fractured plates repaired with composite plates is presented.