Probability of failure can be calculated for all Distribution models. The GE Digital APM system uses the following formula to determine failure probability:
Where:
P(t1|t0) is the failure probability at any given time assuming that the equipment has not yet failed at the current age. If you specify a failure probability, the GE Digital APM system will use this value to calculate the future age of the equipment.
D(t) is the cumulative distribution function, or the failure probability at time t for a new piece of equipment. The curve in the CDF plot represents this function.
t0 is the current age of the piece of equipment.
t1 is the future age of the piece of equipment. If you specify an operating time, this value is determined by adding the time to the current age of the piece of equipment, and the resulting value is then used to calculate the failure probability.
n is the number of subcomponents the piece of equipment contains (e.g., tubes in a heat exchanger bundle). If the failure type of the Reliability Distribution Analysis is Failure with replacement, the number of subcomponents is 1. If the failure type is Failure without replacement, this value is mapped from a query or dataset or manually entered when you create the Reliability Distribution Analysis.
