Parameter | Description |
---|---|
Usage type | The distribution to use to model the reliability of the product or service given its usage period. Choices are Constant and Distribution. The default is Constant. • When Constant is selected, only Usage period and Average use per period are shown. • When Distribution is selected, all parameters but Average use per period are shown. |
Usage period | The number of time units or intervals for which the unit is warranted. The default is 1. Units for the usage period are specified in the field to the right. Choices are Days, Months, and Years. The default is Years. |
Average use per period | The average number of times the unit is utilized during a usage period. This parameter is shown only when Constant is selected for Usage type. The default is 1. |
Interval width | Determines the usage values at which to calculate reliability during the specified usage period. This parameter is shown only when Distribution is selected for Usage type. The default is 1. The distribution selected for the parameter below is used to determine how many units achieve a given usage, which is some multiple of the interval width, in the specified usage period. For example, assuming an interval width of 1000 and a usage period of 1 year, the number of units are determined at usage 1000 after 1 year, at usage 2000 after 1 year, at usage 3000 after 1 year, and so on. Each of these units is entered as a suspension in the linked life data set for this data set, which is specified in Resulting data set in the Weibull Parameters pane. For more information, see Resulting Data Sets on page 12-49. |
Distribution | The distribution to use to model failure times. This parameter is shown only when Distribution is selected for Usage type. Choices are Weibull, Lognormal, Normal, Gumbel- (Lower), Gumbel+ (Upper), Exponential, Rayleigh, Gamma, Logistic, and Log-logistic. The default is Weibull. For distribution descriptions, see Failure and Repair Distributions. |
Model | The method by which to perform the analysis. This parameter is shown only when Distribution is selected for Usage type. The choices available depend on the distribution selected. For more information, see Models Per Distribution. |