When the scale σ (or Weibull shape β), the intercept (β_{0}), and the slope are specified (β_{1}), the standardized intercept is calculated as follows:

The standardized slope is calculated as follows:

Term | Description |
---|---|

σ | specified value for the scale |

β | specified value for the Weibull shape |

specified value for the intercept | |

β_{1} | specified value for the slope |

γ_{0} | standardized intercept |

γ_{1} | standardized slope |

When the scale (or Weibull shape), the slope, and a percentile are specified, the standardized slope and intercept are calculated as follows.

where
for location-scale models (normal, logistic and smallest extreme value)
for log-location-scale models (Weibull, exponential, lognormal and loglogistic)

Term | Description |
---|---|

σ | specified planning value for the scale |

β | specified planning value for the Weibull shape |

β_{0} | intercept |

β_{1} | specified planning value of the slope |

t | specified planning value of a percentile |

Φ^{-1}(p) | inverse CDF of the chosen distribution |

p | proportion of failures at stress level x |

x | stress level |

When the scale (or Weibull shape), the intercept, and a percentile are specified, the standardized slope and intercept are calculated as follows:

for location-scale models (normal, logistic and smallest extreme value)

for log-location-scale models (Weibull, exponential, lognormal and loglogistic)

Term | Description |
---|---|

σ | specified planning value for the scale |

β | specified planning value for the Weibull shape |

β_{0} | specified planning value of the intercept |

β_{1} | slope |

t | specified planning value of a percentile |

Φ^{-1}(p) | inverse CDF of the chosen distribution |

p | proportion of failures at stress level x |

x | stress level |

When the scale (or Weibull shape) and two percentiles are specified, the standardized slope and intercept are calculated as follows.

where:
for location-scale models (normal, logistic and smallest extreme value) and
for log-location-scale models (Weibull, exponential, lognormal, loglogistic)

Term | Description |
---|---|

σ | specified planning value for the scale |

β | specified planning value for the Weibull shape |

β_{0} | intercept |

β_{1} | slope |

t_{1} | specified planning value for a percentile |

t_{2} | specified planning value for a percentile |

Φ^{-1}(p) | standard inverse cdf of the chosen distribution |

p_{1} | proportion of failures at stress level x_{1} |

p_{2} | proportion of failures at stress level x_{2} |

x_{1} | stress level |

x_{2} | stress level |