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Warranty Analysis Repairable Items - WA-RI

Warranty Analysis Repairable Items was developed to analyze warranty claims in a Nevada Chart format.


This module uses the Non-Homogeneous Poisson Process to predict the Warranty Claims. Multiple claims from the same unit are allowed. This is different from the warranty prediction for Non-repairable systems in which only one claim is allowed per unit sold.


Data Type Entry

Nevada Chart

Period Options


Parameter Estimation Methods


Reliability Model


Reliability Plots

Cumulative Number of Failures
Instantaneous MTBF vs. Time
Cumulative MTBF vs. Time
Instantaneous Failure Intensity vs. Time
Cumulative Failure Intensity vs. Time

Reliability Calculations

IMTBF(t) - Instantaneous MTBF
CMTBF(t) - Cumulative MTBF
IFI(t) - Instantaneous Failure Intensity 
CFI(t) - Cumulative Failure Intensity
T(IMTBF) - Time at Instantaneous MTBF
T(CMTBF) - Time at Cumulative MTBF
T(IFI) - Time at Instantaneous Failure Intensity 
T(CFI) - Time at Cumulative Failure Intensity
NOF(t) - Number of Failures
T(NOF) - Time at Number of Failures
Optimum Overhaul Time

Confidence Bounds

Methods: Fisher Matrix / Chi Squared
Confidence Level
Confidence Bounds: Two Sided / Top One-Sided / Bottom-Sided

Other Features

Warranty Claims Forecast Chart
Warranty Claims Forecast Plot
Overlay plots - Multiple items in the same reliability plot
Report - All results and reliability plots in one page
Allow analyze several different items in one analysis
Allow send analysis to other users (R4All and External)

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