Reliability Glossary
Reliability Growth Terms
AMPM
"AMPM" stands for "AMSAA maturity prediction
model." This is an enhanced reliability growth
model that allows the user to predict failure rates in future stages of
development. This model allows the user to assess the effectiveness of proposed
and implemented fixes in order to determine the future failure rate.
AMSAA model
"AMSAA" stands for "Army
Material Systems Analysis Activity." This is
a
reliability growth model that uses a relationship
between cumulative test time and cumulative failures to develop a reliability
growth model.
Duane model
A reliability growth model similar to the AMSAA model that
uses a relationship between cumulative test time and cumulative failures to
develop a reliability growth profile.
Gompertz model
A reliability growth model that models reliability values at different stages of
development, and produces an S-shaped reliability growth curve.
Lloyd-Lipow model
A reliability growth model based on the number of trials and successes at each
stage of product development.
Modified Gompertz model
A reliability growth model that models based on a variation of the
Gompertz model.
NHPP
"NHPP" stands for "non-homogeneous
Poisson process," which is a simple parametric model used to
represent events with a non-constant failure recurrence rate. This type
of model is often used to model
reliability growth and the reliability of repairable
units.
Reliability growth
The analysis of the change in reliability over time, usually applied to products
under development. Reliability growth analysis provides the means by which the
reliability, mean life or failure rate is tracked over time, allowing the user
to predict future reliability values based on the current rate of growth of the
reliability measurement of interest.