Self-checking software: improving the quality of mission-critical systems

Testing of mission-critical systems to a high degree of reliability is a long time problem that continues to plague system integrators. As a result, system failures may occur in the field due to faults that result from unusual environmental conditions or unexpected sequences of events that are never encountered in the laboratory. While the problem is widespread, cost effective and practical solutions have not been forthcoming. This paper reports on a novel technique called self-checking systems that promises a significant step forward in providing a practical approach to improving productivity in the system test and integration process, while producing systems with fewer residual errors. The technique, originally based on theoretical University results, is transitioning to practice under the Air Force Self-Checking Embedded Information System Software (SCEISS) research and development program. A brief introduction will be given to the theoretical roots of self-checking, as well as results obtained from applying result checkers to several important applications. The preliminary results reported here include a description of the example applications and their checkers, the process used to select checkers, and initial data points on any additional costs that may accrue due to the development and test of checkers.