Component based software development approaches represent an important challenge for the integration of formal methods into engineering development processes. In these approaches, components are considered as black boxes communicating through required and provided interfaces which describe their visible behaviors. The development of a system consists in assembling existing components in order to realize system services. The verification of the interoperability between the different components is a crucial issue to guarantee the trustworthy of the system as well as the correct realization of the system needs by the resulting system. We present an approach supported by a rigorous development methodology based on UML~2.0 and the B method, introduced at the level of software architecture. We exploit existing formalisms and their support tools to verify the correctness of component assembly at the protocol level, for the expression of functional properties.