Template:Example: Published 2P Weibull Distribution Interval Data MLE Example

Published 2P Weibull Distribution Interval Data MLE Example

From Wayne Nelson, Applied Life Data Analysis, Page 415 [30]. One hundred and sixty-seven (167) identical parts were inspected for cracks. The following is a table of their last inspection times and times-to-failure:



Published Results:

Published results (using MLE):



Published 95% FM confidence limits on the parameters:



Published variance/covariance matrix:



Computed Results in Weibull++

This same data set can be entered into Weibull++ by selecting the data sheet Times to Failure, with Right Censored Data (Suspensions), with Interval and Left Censored Data and with Grouped Observations options, and using MLE.

Weibull++ computed parameters for maximum likelihood are:



Weibull++ computed 95% FM confidence limits on the parameters:



Weibull++ computed/variance covariance matrix: