Quantitative Accelerated Life Testing (QALT)
In quantitative accelerated life testing, the stresses that cause failure are accelerated under controlled conditions to cause the product to fail in a shorter period of time without introducing failure mechanisms that would not occur under normal use. You can then apply mathematical models to extrapolate to use-level conditions and use this analysis to estimate reliability, mean life, failure rate and other performance measures for the product. This powerful analysis capability can help to significantly reduce test times and produce more robust designs.
Choose the Tool That's Right for You
ALTA provides full support for the analysis of data obtained from quantitative accelerated life tests. The software is available in two versions:
ALTA Standard is intended to be an entry-level tool for the reliability professional interested in basic quantitative accelerated life testing data analysis applications.
ALTA PRO provides advanced capabilities made possible by extensive research and development in complex quantitative accelerated life testing data analysis techniques.
Key features and capabilities are listed below. Some are available only in ALTA PRO. [See Comparison]
Complete Array of QALT Analysis Capabilities
Data Types and Stress Types: ALTA's data entry spreadsheets support complete, right censored (suspended), interval or left censored data, entered individually and in groups. ALTA Standard provides models for one or two stress types. ALTA PRO offers models that can analyze up to 8 stress types.
Life-Stress Relationship Models: ALTA supports data analysis with the Weibull, lognormal and exponential distributions combined with the following life-stress relationships: Arrhenius, Eyring, Inverse Power Law, Temperature-Humidity and Temperature-Nonthermal. ALTA PRO also includes more advanced multi-stress and time-dependent stress models, including Generalized Eyring, Proportional Hazards, General Log-Linear and Cumulative Damage.
Time-Dependent Stress Profiles: In ALTA PRO, you can define stress profiles that vary with time, such as step-stress, ramp-stress, etc.
Parameter Estimation and Calculated Results: ALTA uses Maximum Likelihood Estimation (MLE) for parameter estimation. The QCP and Function Wizard quickly return calculated reliability results (such as reliability given time, mean life, acceleration factor, BX% life, etc.) based on the data analysis and your inputs. When applicable, ALTA also provides confidence bounds for parameters, calculated results and plots.
Plots and Automated Reports: The software automatically generates a complete array of reliability plots, with customizable settings. Plots can be annotated and exported as graphic files for use in your reports and presentations. Automated report generation is also available.
Accelerated Test Planning Utility: ALTA offers a choice of methods for designing an effective one-stress or two-stress accelerated life test plan. Based on your inputs about the expected failure behavior and available test time, the utility recommends the stress levels and the most effective allocation of units to be tested at each level.