Describing software architectures by system structure and properties

To support architecture based development, different modeling notations and languages, so called architecture description languages (ADLs), have been designed. To be of help in the development process, software architectures must be described in a complete and consistent manner but without being overloaded with information provided to the system stakeholders. Current architecture description languages provide information about software architectures in a domain independent way. This may lead to inappropriate and incomplete descriptions of software architectures. We introduce a flexible and extensible language called Architecture Structure Description Language (ASDL) developed for describing structural aspects of software architectures and their properties. We thereby focus on the domain of embedded real time systems that have to meet certain timing and safety constraints. The language was developed in an architecture recovery process of a real world Train Control System (TCS) and has been used to describe and reason about TCS's architecture.