System Safety - A Quantitative Fallout from Reliability Analysis 670684
This paper presents a method to quantitatively evaluate the safety of a system by utilizing existing reliability techniques and data. The premise this paper develops is that crew safety is a special case of system safety. Therefore, the reliability analyses and mathematical models developed to evaluate crew safety are considered applicable to a system safety analysis. System safety will be developed as the probability of successfully completing or safely aborting a given operation or test.
The relationship and utility of crew safety mathematical models, failure mode-effect analyses, criticality analyses, critical items lists, component failure data, and system effectiveness are discussed. The methodology developed for the display of system safety as a probability is the extension, reorientation, and selective utilization of these techniques and analyses. This is accomplished by 1) extension of these analyses to other than flight systems and/or mission operations, and 2) consideration of a safe abort capability through utilization of operating personnel or automatic sequencing to initiate corrective measures to avert a potentially hazardous situation. The advantages of system safety being developed as a product of an existing technology include maximum utilization of existing procedures, data, and computer programs, resulting in an overall program cost effectiveness. The advantage of system safety being developed as a quantitative figure of merit is its utilization as a parameter of system effectiveness.