Tag Archives: Conditional failure probability
Random failure is exponential reliability decay
When something decays or grows “exponentially” it means that it changes regularly by a constant factor. An example of exponential growth is the principle in a compound interest bank account which increases at regular intervals by a constant factor. Assume that you … Continue reading
Conditional failure probability, reliability, and failure rate
What is the relationship between the conditional failure probability H(t), the reliability R(t), the density function f(t), and the failure rate h(t)? In the article Conditional probability of failure we showed that the conditional failure probability H(t) is: X is the failure … Continue reading
Conditional probability of failure
The most powerful information sought by all maintenance engineers and managers boils down to the conditional failure probability. It is the probability of an item failing in an upcoming period of interest knowing that it is currently in an unfailed state. If you … Continue reading
Posted in Reliability Analysis, Theory and definitions
Tagged Conditional failure probability
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Random failure and the MTTF
Nowlan and Heap said that the (conditional) probability of occurrence of most failure modes is constant throughout the life of a component. They described this behavior as being that of “random” failure. What is the Mean Time to Failure (MTTF) of a randomly … Continue reading
Conditional probability of failure vs. hazard rate
John Moubray, as a warning against being too sure of oneself, used to tell this story to his aspiring RCM consultants: A newly trained RCM practitioner consultant was delivering the standard three-day RCM course to a group of his clients, … Continue reading