Research On Human Factors In Functional Safety And Its Quantitative Analysis

Functional safety of safety-related systems is one of the most important safety conceptions in area of process industry. The standard recognizes the need to address 'human factors', but provides minimal guidance as to what this entails. At the same time, the objects of existing research on the impact of human factors are focus on operators; the contents of existing research are focus on analyzing and preventing the mistakes of operators. The researches on the mistakes of analyst and developer are rarely involved. This paper explores various issues that are involved in addressing human factors in two aspects under IEC61508. One is the activity influences of safety-related system stakeholders on the functional safety, anther is how to eliminate the analyst and developer mistakes with quantitative methods. The research and achievements of this dissertation covers the following:1. In order to define the. human factor oversights of current functional safety standard, existing human factors requirements within IEC61508are reviewed, and the omissions in the standard are perfected. A human factor safety management has been established.2. A concept of human factor safety integrity is proposed to handle the problems in human factor safety management. A proposed framework is introduced with the purpose of human factor safety integrity assessment.3. A new intuitionistic fuzzy set distance is proposed to handle the consistency problems in the process of hazard analysis. The availability and affectivity of the proposed distance are discussed. The detail about consistency of hazard analyst based on intuitionistic fuzzy set theory is described, and then an example is taken.4. In order to address the problems about accuracy of risk assessment, an intuitionistic fuzzy described risk is taken. A new construction of risk matrix based on intuitionistic fuzzy set is proposed, and then an example is taken.5. In order to address the problems about calculation of dependent failure rates, a model based on hypergraph for dependent failures is proposed, and then an example is taken.