Augmenting T&E with Assurance
SEI work on the use of assurance cases in the development of medical devices led directly to the FDA issuing draft guidance to manufacturers recommending the use of assurance cases and providing guidance for their use. As a result, infusion pump manufacturers are beginning to make use of assurance cases.
It is difficult to assure the safety, security, or reliability of net-centric systems of systems because of their size, complexity, and continuing evolution—and because they can exhibit undesired and unanticipated emergent behavior. (Emergent behavior is the actions of a system as a whole that are not simple combinations of the actions of the individual constituents of the system.)
Traditional software and systems engineering techniques, including conventional test and evaluation approaches, cannot provide the justified confidence needed. The SEI is developing an assurance case methodology to augment testing and evaluation.
The assurance case provides a means to structure the reasoning that engineers use implicitly to gain confidence that systems will work as expected. It also becomes a key element in the documentation of the system and provides a map to more detailed information.
The concept of an assurance case was derived from the safety case, a construct that has been used successfully in Europe for over a decade to document safety for nuclear power plants, transportation systems, automotive systems, and avionics systems.