We have developed an incremental development framework which supports progressive constructions of UML state machines. This framework includes behavioral refinement and extension verifications. In this paper, we extend this framework to UML composite components in order to guide architecture modeling and verification. It consists of a set of construction techniques which assist the designer in two complementary ways: concerning behavioral aspects, the techniques are based on formal relations which determine if the new architectures are true refinement and/or extensions of the former ones; concerning structural aspects, the techniques contribute to the software engineering design principles separation of concerns, information hiding and hierarchical modeling. The paper presents some of these techniques and illustrates them through a case study.