Failure Distributions Records

A Failure Distributions record stores information about the distribution of failures over the life of the spare part that you are analyzing. The following table provides an alphabetical list and description of the fields that exist for the Failure Distributions family and appear on the Failure Distributions tab in the workspace for a Spare by default.

This family is enabled for site filtering, which means that records in this family can be assigned to a specific site, and will then only be accessible to users who are assigned to the same site and have the appropriate license and family privileges. See the Site Filtering section of the documentation for more information on using this feature.

Field	Data Type	Description	Behavior and Usage
Distribution Type	Character	The distribution type of the Failure Distribution.	For Failure Distribution information that you want to define manually, a list appears in which you can select the desired value. The value is set to Exponential by default, but you can select any of the following additional distribution types: Weibull Normal Lognormal For Failure Distribution information that you have imported, this column displays the read-only distribution type of the analysis from which you have imported failure distribution information.
Name	Character	The name of the Failure Distribution.	This is a required field. The name of each Failure Distribution must be unique to the root Spare Application record. This field is labeled Distribution Name on the datasheet. For Failure Distribution information that you want to define manually, you can enter a name in the Distribution Name field. For Failure Distribution information that you have imported, the Distribution Name field displays the hyperlinked value that is stored in the Analysis ID field in the Reliability Distribution or Reliability Growth record with which you associated failure distribution information. You can select the hyperlink to open the analysis.
<Parameter 1>	Number	The value of the <Parameter 1>	Displays one of the following parameters, depending on the distribution type: For a Weibull distribution, displays the Beta value. For an Exponential distribution, displays the Mean Time Between Failures value. For a Normal distribution, displays the Mean value. For a Lognormal distribution, displays the Mu value. By default, values up to four decimal places are displayed in the <Parameter 1> column. If you select a cell in the <Parameter 1> column for a parameter that can be modified, all decimal places for the value will be displayed.
<Parameter 2>	Number	The value of the <Parameter 2>	Displays one of the following parameters, depending on the distribution type: For a Weibull distribution, displays the Eta value. For an Exponential distribution, nothing is displayed. The Mean Time Between Failures value that is displayed in the <Parameter 1> column is the only parameter in an Exponential distribution. For a Normal distribution, displays the Standard Deviation value. For a Lognormal distribution, displays the Sigma value. By default, values up to four decimal places are displayed in the <Parameter 2> column. If you select a cell in the <Parameter 2> column for a parameter that can be modified, all decimal places for the value will be displayed.
<Parameter 3>	Number	The value of the <Parameter 3>	Displays one of the following parameters, depending on the distribution type: For a Weibull distribution, displays the Gamma value. For an Exponential distribution, nothing is displayed. The Mean Time Between Failures value displayed in the <Parameter 1> column is the only parameter in an Exponential distribution. For a Normal distribution, nothing is displayed. The Mean and Standard Deviation values that are displayed in the <Parameter 1> and <Parameter 2> columns are the only parameters in a Normal distribution. For a Lognormal distribution, displays the Gamma value. By default, values up to four decimal places are displayed in the <Parameter 3> column. If you select a cell in the <Parameter 3> column for a parameter that can be modified, all decimal places for the value will be displayed.
Time Unit	Character	The unit of measure that applies to the distribution type that appears in the Distribution Type column.	For Failure Distribution information that you want to define manually, a list appears in which you can select the desired value. The value is set to Days by default, but you can select any of the following additional units of measure: Hours Weeks Months Years For Failure Distribution information that you have imported, this column displays the read-only unit of measure used in the analysis from which you have imported Failure Distribution information.