Modeling and plotting functions for Reliability Growth Analysis (RGA). The package implements three families of models and provides a REST API interface via plumber.
Crow-AMSAA (NHPP power-law)
The core model fits a Non-Homogeneous Poisson Process (NHPP) with a Weibull intensity function to cumulative failure data. Parameters are estimated by least-squares log-log regression (default) or maximum likelihood. A growth rate > 0 indicates reliability improvement.
Piecewise NHPP
Extends Crow-AMSAA by fitting separate NHPP segments separated by change points. Change points can be detected automatically via the segmented package or supplied by the user.
Duane
Log-log regression of cumulative MTBF versus cumulative time, providing a graphical and analytical representation of reliability growth.
| Function | Description |
rga() | Fit Crow-AMSAA or Piecewise NHPP model |
predict_rga() | Forecast cumulative failures from a fitted model |
duane() | Fit Duane model |
rdt() | Reliability Demonstration Test plan calculator |
weibull_to_rga() | Convert Weibull data to RGA format |
sim_failures() | Simulate failures from a conditional Weibull model |
qqplot.rga() | Q-Q goodness-of-fit plot for an rga object |
ppplot.rga() | P-P goodness-of-fit plot for an rga object |
grwr_api() | Launch the plumber REST API |
| Class | Methods |
rga | print.rga(), plot.rga() |
rga_predict | print.rga_predict(), plot.rga_predict() |
duane | print.duane(), plot.duane() |
rdt | print.rdt() |
Maintainer: Paul Govan paul.govan2@gmail.com (ORCID) [copyright holder]
Crow, L. H. (1975). Reliability Analysis for Complex Repairable Systems. AMSAA Technical Report No. 138. US Army Materiel Systems Analysis Activity.
Duane, J. T. (1964). Learning curve approach to reliability monitoring. IEEE Transactions on Aerospace, 2(2), 563–566. tools:::Rd_expr_doi("10.1109/TA.1964.4319640")
Guo, H., Mettas, A., Sarakakis, G., & Niu, P. (2010). Piecewise NHPP models with maximum likelihood estimation for repairable systems. In Proceedings of the 2010 Annual Reliability and Maintainability Symposium (pp. 1–6). IEEE. tools:::Rd_expr_doi("10.1109/RAMS.2010.5448029")
Muggeo, V. M. R. (2024). segmented: Regression Models with Break-Points / Change-Points Estimation. R package. https://cran.r-project.org/package=segmented
Useful links: