Statistical Methods and Overview
Reliability is equal to 1 minus this
Probability of failure
A pipeline rupture is an example of this type of limit state.
Ultimate Limit State
Sum of the values divided by the number of measurements
Mean
The effect of operational changes or maintenance actions can be quantified with this.
Reliability assessment
The increments on this type of scale are orders of magnitude.
Logarithmic
Type of regression that is used for a binary response variable
Logistic regression
Mathematical function that defines the boundary between safe operation and failure
Limit State Function
These two parameters define a normal distribution
Mean and Standard Deviation
Pressure decreases have this effect on the probability of burst failure.
Reduction
Risk is these two terms multiplied together
Probability and Consequence
1 percent in scientific notation (eg. 10x)
10-2
Safety factors are typically based on this
Past experience and engineering judgment
The term for a distribution with two 'peaks'.
Bi-modal
A method that involves randomly sampling a large number of simulated experiments.
Monte Carlo
The type of chart that illustrates the relative frequency of values in a dataset.
Histogram
Logic Gate that multiplies the input probabilities
AND Gate
Instead of historical failures, Structural Reliability Methods are based on this.
The physics of failure
Percentage of data within one standard deviation in a normal distribution
~68%
The proportion of simulations in Monte Carlo that fail the limit state is an estimate of this.
Probability of Failure
Fault trees have been broadly adopted in this industry.
Nuclear
Event in a fault tree that is not broken down further
Basic Event
Model uncertainty quantifies this.
The difference between engineering models and reality
The two main aspects of data that descriptive statistics could summarize
Central Tendency and Variation
The general and location-specific checks evaluate these two types of life safety risk.
Societal and Individual
The mean multiplied by the Coefficient of Variation.
Standard Deviation