All the Options You Need for Life Data Analysis
Parameter Estimation Options
The Weibull++ standard folio supports all life data types and all major lifetime distributions used in reliability engineering statistics. You can analyze time-to-failure (complete), right censored (suspension), left censored, interval censored or free-form data, entered individually or in groups. Available lifetime distributions include:
- 1, 2 and 3 parameter Weibull
- 1 and 2 parameter Exponential
- Normal and Lognormal
- Gamma and Generalized Gamma
- Logistic and Loglogistic
The following special analysis methods are also supported:
- The Bayesian-Weibull analysis method considers prior knowledge of the Weibull shape parameter.
- 2, 3 and 4 subpopulation Mixed Weibull analysis can be used for situations when there are different trends in the data but you cannot identify a distinct failure mode for each data point.
- The Competing Failure Modes (CFM) method analyzes each failure mode separately and then assumes a series reliability model in which the failure modes "compete" to cause the failure.
- New in Version 10, you can use Fractional Failure Analysis to account for the effectiveness of an assumed corrective action or product redesign in your analyses.
If you are not sure which model is appropriate for a given data set, the convenient Distribution Wizard automatically performs several types of goodness-of-fit tests in order to rank the available distributions.
Parameter Estimation options for standard life data analysis include Maximum Likelihood Estimation (MLE), Rank Regression on X (RRX) or Rank Regression on Y (RRY).
Weibull++ also provides Confidence Bounds for parameters, calculated results and plots. Depending on the specific analysis method used, the confidence bounds may be calculated using the Fisher Matrix, Likelihood Ratio, Beta Binomial or Bayesian approach.
Calculated Results and Plots
The software provides a complete array of Calculated Results and Plots based on the analysis. For life data analysis, this includes:
- Reliability or probability of failure
- Reliable life (i.e., time for a given reliability, also called "warranty time")
- BX% life (i.e., time for a given unreliability)
- Mean life
- Failure rate
- Probability plots and pdf plots
- Contour plots
- Failure/suspension histograms, pie charts or timelines
The Quick Calculation Pad (QCP) has been updated and redesigned in the Synthesis version. The new interface provides a "Calculation Log" that works like a paper roll in an adding machine, allowing you to record the results from a series of different calculations and then copy/paste the information as needed.