The purpose of this book is to introduce a systematic method for the integrated layout design of the components packing and structural patterns of the multi-component systems. In view of the common design requirements of aerospace structural systems, the integrated design is studied as a simultaneous optimization procedure in this work. The method of FCM is firstly developed to solve the packing problems. Using certain numbers of circum- circles to describe the contour of the components and the design domain approximately, the complex geometry constraints are transformed into some distance functions of explicit form. The gradient- based algorithms can be applied accordingly. The idea of integrating the packing and topology optimization is then proposed. The location and orientation of the components are defined as the geometrical design variables. By using FCM to avoid the overlaps, proper layout of the components is found by the optimization procedure. Simultaneously, the topology optimization is carried out to generate structural layout supporting the components.