Assembling components into an architecture is a difficult task because of its combinatorial complexity. There is thus a need for automating this building process, either to assist architects at design time, or to manage the self-assembly of components at runtime. This paper proposes an automatic architecture building process that uses ports, and more precisely composite ports, to manage the connection of components. Our solution extends the Fractal component model. It has been implemented and experiments have been run to verify its good time performance, thanks to several optimization heuristics and strategies.