The ASSL formalism for real-time autonomic systems

To increase the overall reliability, modern computerization of complex systems such as spacecraft, airplanes, and automobiles strives to minimize the human control via self-adaptation. In such systems, special autonomic components are designed to handle performance problems via monitoring and automatic decision making. Successful development of autonomic systems requires new software development approaches. ASSL (Autonomic System Specification Language) is a framework dedicated to the development of autonomic systems whereby developers are helped with problem formation, component and system design, analysis, evaluation, and implementation. The bottom line is a special multi-tier specification mechanism exposing a rich set of constructs allowing a system to be modeled by emphasizing different key aspects, but centering the model around special self-management policies. This entry presents in detail the aforementioned mechanism together with the underlying semantics. As a case study, we also present an ASSL specification model for autonomic components of an autonomous NASA space exploration system.