Int J Performability Eng ›› 2008, Vol. 4 ›› Issue (1): 71-84.doi: 10.23940/ijpe.08.1.p71.mag

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Epistemic Uncertainty Propagation in Reliability Assessment of Complex Systems

K. DURGA RAO1, H.S. KUSHWAHA1, A.K. VERMA2, and A. SRIVIDYA2   

  1. 1Bhabha Atomic Research Centre, Mumbai, India
    2Indian Institute of Technology Bombay, Mumbai, India

Abstract:

Uncertainties are present in any reliability calculations due to randomness in the failure/repair phenomena and given the limitation in assessing the parameters of the failure/repair probability density functions. The simplifications and idealizations also generate uncertainties which can be classified as aleatory (arising due to randomness) and/or epistemic (due to lack of knowledge). It is very important to identify all the uncertainties and treat them effectively to make reliability studies more useful for decision making. The uncertainty propagation of system reliability assessment quantifies uncertainty in system characteristic (e.g. system unavailability) by synthesizing the uncertainties in component characteristics. This paper explores various uncertainty propagation methods used in availability assessment of complex engineering systems. Apart from probabilistic (analytical and sampling) and fuzzy arithmetic approaches, Dempster-Shafer theory based approach is attempted to deal the same problem. A case study on Main Control Power Supply System (MCPS) of typical Indian Nuclear Power Plant (NPP) is presented highlighting merits and demerits of various methods.
Received on Feb.11, 2007
References: 40