Componentware introduces a new software development paradigm. Systems are no longer implemented from scratch, but glued together from existing components - similar to the successful model from the building industry.

However, today's component-based software development approaches are mainly influenced by discussions on the underlying technical infrastructure. The model of the building industry was not completely transferred to component-based software development. This is partly due to the lack of a suitable componentware methodology. Such a methodology should at least incorporate the following parts:

• a well-defined conceptual framework of componentware is required as a reliable foundation.
• based on the formal model, specification techniques for components and component-based systems are needed.
• Component-based development should be organized according to a process model tailored to the specific needs of component vendors and component users.

In this talk we will introduce a formal model for components and component-based systems to unambiguously express the basic definitions and concepts, like interfaces, components and connections. These concepts are as simple as possible, yet sufficiently powerful to capture the essential concepts and development techniques of existing component-based infrastructures.

As it turns out, today's specification techniques are not sufficiently powerful to specifiy component-based systems. We show how these techniques can be leveraged to its full extent for component-based systems. Finally we provide the theoretical foundation of the proposed specification techniques based on the presented formal model.