Studies on common cause failures are numerous. Little is done on the effect of common cause failure on measures of system effectiveness like mean time to system failure (MTSF). This paper deals with the modeling and evaluation of MTSF of 2-out-of-5 warm standby repairable system with replacement at the occurrence of each common cause failure. Using Kolmogorov’s forward equations method, derivat...

An underlying assumption for N-version programming technique is that independently developed versions would fail in a statistically independent mannel: Howevel; empirical studies have demonstrated that common mode failures can occur even for independently developed versions, and that common mode failures degrade system reliability. In this papel; we demonstrate that the weakest precondition ana...

A condition based preventive and corrective maintenance policy is proposed for a continuously operating system. The condition of the system is assumed to deteriorate with time. The model incorporates both deterioration as well as random common cause failures. The deterioration stages are modeled as discrete state processes. The system is put to random inspection to know the condition. The mean ...

Starting with the meaning of the word quality, diverse concepts connoted by the term are examined. Instead of a bathtub curve, the desirable shape of a failure rate covering the entire life of a good product, which might be called hockey-stick line, is introduced. From the hockey-stick line and the definition of reliability, two measurements are extracted. The terms r-reliability (failure rate)...

Reliability is one of the most important quality dimensions for web services. Current reliability models for composite web service assume the statistical independence of its component web services, which is often not the case. In this paper, we research on the reliability correlation of component web services by identifying common-cause failures (CCF) and propose a tree-based reliability model ...

Traditional Probabilistic Risk Assessments (PRAs) model dependency through deterministic relationships in fault trees and event trees, or through empirical ratio common cause failure (CCF) models. However, popular CCF models do not recognized system specific defenses against dependencies and are restricted to identical components in redundant configuration. While this has allowed prediction of ...

The level of understanding of adhesive bond failures within the flight safety community is not as robust as it could be. Generally, most investigators are broadly aware of cohesion failure (fracture of the adhesive) and adhesion failure (a slick failure at the interface). They may also have some limited knowledge of common causes for bond failures such as bond-line voids, which is one cause of ...

Failure of multiple components due to a common cause represents one of the most important issues in evaluation of system reliability or unavailability. The frequency of such events has relatively low expectancy, when compared to random failures, which affect individual components. However, in many cases the consequence is a direct loss of safety system or mitigative safety function. For this re...