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Lo standard di settore per l'analisi dei dati sulla vita reale

Life data types, distributions and parameter estimation


Weibull++ supports all types of life data analysis, including:

  • Complete (failure time)
  • Right censored (suspension time)
  • Left censored
  • Interval censored
  • Free-form

Parameter estimation options for standard life data analysis include: 

  • Rank Regression on X (RRX)
  • Rank Regression on Y (RRY)
  • Maximum Likelihood Estimation (MLE)
  • Non-Linear Rank Regression
  • Fractional Failure Analysis

All major lifetime distributions (including all forms of the Weibull distribution) are also supported:

  • Weibull
  • Normal and Lognormal
  • Exponential
  • Gamma and Generalized Gamma
  • Logistic and Loglogistic
  • Gumbel
  • Bayesian-Weibull
  • Mixed Weibull
  • Competing Failure Modes (CFM)

Distribution wizard and ranking methods


If you are not sure, which model is appropriate for a given data set, the Distribution Wizard automatically performs several types of goodness-of-fit tests (Kolmogorov-Smirnov, Correlation Coefficient, Likelihood value) in order to rank the available distributions. It comes also with the ability to rank data points using Kaplan-Meier or Median Ranks.

Confidence bounds

Weibull++ 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 (BSN) approach.

Reliability test design

Reliability demonstration test design determines the appropriate sample size, test duration or other variables for designing effective reliability tests and demonstration tests. Expected failure times plot displays times-to-failure that you may expect to observe for a given reliability life test.


Difference detection matrix allows you to detect the difference between the reliabilities of two separate designs.

Warranty data analysis


A choice of data entry formats available for using sales/returns data to perform life data analysis and make warranty projections: nevada chart, times-to-failure, dates of failure and usage (e.g., mileage, cycles, etc.), as well as the time.

Degradation data analysis


Use the linear, exponential, power, logarithmic, Gompertz or Lloyd-Lipow models to extrapolate the failure times of a product based on its performance (degradation) over a period of time. Weibull++ also includes destructive degradation analysis and the option to create user-defined degradation models.

Reliability block diagrams

The built-in diagram feature allows you to create reliability block diagrams (RBDs) using blocks that are linked to analyzed Weibull++ folios. This feature can be used to analyze complex competing failure modes or simple system reliability. You can even send RBDs built in Weibull++ to BlockSim. This process exports the blocks into a new BlockSim simulation diagram, allowing you to perform further analyses such as system maintainability, availability and related analyses.

Design of experiments (DOE)

Weibull++ supports a variety of experiment design types, including factorial and fractional designs, Taguchi robust designs, response surface method designs, and DOE based on product life, called reliability DOE.

Life data results, plots, and reports

The Quick Calculation Pad (QCP) is a "Calculation Log" that allows you to record the results from a series of different calculations and then copy/paste the information as needed.

The software also provides a complete array of calculated results and plots based on the analysis. For life data analysis, this includes:

  • Reliability or probability of failure
  • Conditional reliability or conditional probability of failure
  • Reliable life (i.e., time for a given reliability, also called "warranty time")
  • Probability plots and pdf plots
  • Contour plots
  • Failure/suspension histograms, pie charts or timelines
  • BX% life (i.e., time for a given unreliability)
  • Mean life
  • Failure rate


Weibull++ provides a complete array of advanced plotting tools. The Plot Setup allows you to completely customize the "look and feel" of plot graphics. You can save your plots in a variety of graphic file formats for use in other documents.

  • Overlay Plots (aka Multi-Plots)
  • Side-by-Side Plots
  • RS Draw® Metafile Graphics Editor
  • 3D Plots


Customizable reports are also built into Weibull++. They seamlessly integrate spreadsheet and word processing capabilities while enabling you to include calculated results and plots from your analysis.

Accelerated Life Testing module

When you purchase the Accelerated Life Testing module, you get new features in Weibull++ designed for accelerated test planning and quantitative accelerated life testing data analysis. The module supports a complete array of utilities for designing accelerated life tests, evaluating the fit of the model, calculating reliability metrics, generating plots and performing related statistical analyses. Additionally, it provides the life-stress relationships required to analyze accelerated life test data with up to 8 simultaneous stress types, where stress is constant or varies with time.

Reliability Growth module


When you purchase the Reliability Growth module, you get new features in Weibull++. Using reliability growth models, you can analyze data from both developmental testing and fielded repairable systems. During the development phase, you are able to quantify and track the system’s reliability growth across multiple test phases. The module supports advanced methods for reliability growth projections, planning and management.