Quality and Safety Factors in Reliability

• Main Author: Ghare, P. M
• Format: Report
• Language: English
• ISSN: 0148-7191; 2688-3627
• DOI: 10.4271/700655

The objective of this paper is to describe the reliability of a system component as a function of both a) the safety factor used in the design and b) the quality factor associated with the production of the component. Under the normal operating conditions the component is subjected to some environmental stress and to withstand this stress the component is designed with a safety factor ν. In practice the design of the component is broken down into individual dimensions and the production specifications are derived for these dimensions. The strength of the components (when produced) would consequently be function of the quality of production. Thus it is possible to describe the reliability as a function of both the safety factor ν and quality of production q. This function is computed, for specific assumptions, and the graphs are included in the paper. The principal advantage of this analysis would be the recognition of a possible trade-off within the resources allocated to better production and those assigned to higher safety factors. The same reliability would be achieveable either through a very high safety factor with poor production quality or through a lower safety factor with better production quality. The optimal resource allocation could be obtained through the solution of a mathematical programming problem.