Specify the distribution fitting for Distribution ID Plot

Select the method to use to estimate the distribution parameters. Also, select percentiles to display in the results.

Estimation Method

• Maximum Likelihood: Estimate the distribution parameters by maximizing the likelihood function.
• Least Squares (failure time(X) on rank(Y)): Estimate the distribution parameters by fitting a regression line to the points on a probability plot.

For more information on these two methods, go to Least squares estimation method and maximum likelihood estimation method.

Estimate percentiles for these percents

Enter the percents for which you want to estimate percentiles. A percent for a percentile is the percentage of items that are expected to fail by a particular time (percentile). Therefore, each value that you enter must be between 0 and 100 and should indicate the percentage of items that will fail. The nth percentile has n% of the observations below it, and (100 – n)% of observations above it.

By default, Minitab estimates the 1st, 5th, 10th, and 50th percentiles. To examine the end of the product's lifetime, enter a higher value. For example, if you enter 90, Minitab estimates how long it takes for 90% of the units to fail.