System Safety Engineering― An Indispensable Element of Reliability Engineering

摘要

General reliability considerations during the design phase are manifested through identification of system failures. Some of these failures will create safety hazards. Analyzing these hazards s often difficult because of the low probabilities of occurrence and usually unknown effects if and when the hazards occur. The low probabilities are often the result of the robust design engineering that has reduced the catastrophic failures to a minimum. Not enough statistical data exist on the probabilities of failures c ' the total system. Most reliability testing events are executed on the lower level and not on the sy tern level. Also major catastrophic accidents have rarely occurred because of the failure of one co nponent. Failure of an individual component is too easy to predict in advance, and therefore, too difficult to ignore. Rather, accidents occur following a chain of events and they usually consist of any combination of human error, equipment failures, faulty maintenance, and software glitches. This paper intends to explore the various inter-connected links that exist betv een System Safety and Reliability Engineering by discussing failures (focusing on software), human e rors, and the analytical methods currently being used in detecting, eliminating, and controlling hazards/risk .