A shock model for common-cause failures

✍ Scribed by Per Hokstad

• Publisher: Elsevier Science
• Year: 1988
• Tongue: English
• Weight: 916 KB
• Volume: 23
• Category: Article
• ISSN: 0951-8320
• DOI: 10.1016/0951-8320(88)90018-x

✦ Synopsis

A BSTRA CT

This paper deals with the modeling of common-cause failures in redundant systems. Two of the well-known models for common-cause failures, the fl-.factor and the binomial failure rate (BFR) model, are discussed and evaluated. Applicability and shortcomings of these models are pinpointed. Further, a new parametric model for common-cause failures, here denoted the random probability shock ( RPS) model, is suggested. The main feature of this model is the ability to model various degrees of dependence between the components of the system in a rather straightforward way. The fl-factor and BFR models are special cases of this new model NOTATION 2

Total failure rate of one specific component 2 i Component rate of independent failures 2 d

Component rate of dependent failures (i.e. failures that might also affect other components) 2s(k) Rates of system errors, in which exactly k components fail. Here k (= 1, 2,..., n) is the so-called failure multiplicity v Rate of system shocks causing dependent failures. fk Probability of k (= 0, 1,..., n) components failing, given that a shock has occurred (fk is the multiplicity distribution) n Number of redundant components m the system Note that the three first failure rates refer to a specific component (here 2 = 21 + 2d). The rates 2s(k) describe the system.