THE COMPREHENSIVE LIFECYCLE FOR ASSURING SYSTEM SAFETY – CLASS
John Knight, Professor of Computer Science, University of Virginia and President, Dependable Computing LLC and Kimberly Wasson, Dependable Computing LLC
September 9, 2015, 2:00 pm, NIA, Rm 137
CLASS is a novel approach to the enhancement of system safety in which the system safety case becomes the focus of safety engineering throughout the system lifecycle. CLASS also expands the role of the safety case across all phases of the system’s lifetime, from concept formation to decommissioning.
The concept of having the system safety case be the focus of safety engineering only has value if the safety case is well maintained and always consistent with the system. If the safety case is not consistent with the system then belief in a safety claim might not be justified. Maintaining consistency establishes a property referred to as synchrony. Synchrony requires that a system and its safety case be regarded as a pair or a couple, always linked and always correctly representing one another. This notion of maintaining synchrony is one of several fundamental principles upon which CLASS is built.
CLASS introduces new techniques for the creation, certification and maintenance of safety cases, a set of novel technical concepts in the field of safety engineering and safety argumentation, a rigorous analysis mechanism for both certification and the complete CLASS that allows determination of properties of both that relate to defect detection in subject systems, and a set of software tools that are incorporated into Dependable Computing’s Safety Case Toolset.
This presentation will summarize the concepts that CLASS introduces and discuss early results obtained from application of the technology to a prototype avionics application.
John Knight is a professor of computer science at the University of Virginia. He holds a B.Sc. (Hons) in Mathematics from the Imperial College of Science and Technology (London) and a Ph.D. in Computer Science from the University of Newcastle upon Tyne. Prior to joining the University of Virginia in 1981, he was with NASA’s Langley Research Center.
Dr. Knight’s primary research interests are the practical application of mathematical proof in the assurance of safety- and security-critical systems, and the development of rigorous safety- and security-cases that document rationale for belief in safety and security claims.
Dependable Computing LLC is an applied research and technology transfer company that Dr. Knight founded in 2009. Research at Dependable Computing focuses on practical development of large safety cases and proofs of safety properties in model-based development. Customers include the US Navy, the US Air Force, NASA, DARPA, and Toyota Motors.
Kimberly Wasson is a Principal Scientist at Dependable Computing, LLC. She holds a B.A. in Russian from Syracuse University, an M.A. in Slavic Linguistics from the University of Virginia, and a Ph.D. in Computer Science from the University of Virginia. Dr. Wasson’s primary research and practice interests are in the application of structured argument bases to the engineering and certification of complex, safety-critical systems. In particular, she develops and deploys strategies and infrastructure to enable the maturation of large safety cases at scale, to meet the challenges imposed by organizational dynamics and stakeholder communication, and to integrate these supports with existing and future certification requirements.