Tagged Part If marked, specifies the part as a tagged part. The designation of tagged part is used as an option in reporting, allowing you to report on tagged parts only.
Repairable Item Enable the repairable item checkbox if the part is repairable. Otherwise, disable it. This information is used only for maintainability calculations.
Part Number Represents the part number of the item in the parts list. You may enter an alphanumeric part number up to 255 characters in length.
Category The category for the part.
Subcategory The subcategory for the part.
Reference Designator
The reference designator, e.g. U1, R22, C1-C15, for the part.
Quantity The quantity for the part. You have the option of entering fractional quantities.
Model You may select a different reliability prediction model on a part by part basis. If no model is selected, the calculation for the part is based on the model selected
Field Description
Alternate Part
Number Alternate part number for the selected part. You may enter any alphanumeric information up to 255 characters.
CAGE Code Commercial and Government Entity Code of the selected item. Normally a 5-digit code, but you can enter up to 255 characters.
Description Description of the selected part. You may enter any alphanumeric information up to 255 characters.
Logistics Control Number (LCN)
Used when exporting information to a MIL-STD-1388 2B compatible format.
The Logistics Control Number field allows you to specify the LCN.
Cost Cost of the selected part. The cost can be entered in any unit that you select, but you should be consistent.
User-defined
Text Text field of information for your own use, storing up to 255 characters.
User-defined
Value Numerical field of information for your own use.
Failure Rate Calculated. Specifies that the failure rate is to be calculated based on the selected calculation models.
Failure Rate Specified. Specifies the failure rate for the part. If a value is entered, no calculation is completed for the part. The unit of the failure rate entered is based on the failure rate multiplier specified on the Project Definition Tab in the System Properties.
MTBF Specified. Specifies the Mean Time Between Failures (MTBF) of the element. If a value is entered, no calculation is completed for the part. The unit for MTBF is always hours.
Multiplicative Adjustment
An adjustment factor that is multiplied by the failure rate to calculate the adjusted failure rate.
Additive
Adjustment An adjustment factor which is added to (or subtracted from) the failure rate to calculate the adjusted failure rate. You may enter a positive or negative value.
Prediction Data Tab
The Prediction Data tab is used to enter information required to perform a reliability prediction. The appearance and items on the Prediction Data tab depend entirely on which category and subcategory are entered on the Parts Table for the selected part. Information on these specific forms is obtained by accessing the online help system by pressing <F1>.
FMEA Data Tab
The FMEA Data tab is used to enter information required to perform a Failure Mode and Effects Analysis (FMEA). The fields of information on the FMEA Data tab depend entirely on the FMEA Input Format file that was selected for the particular project.
Maintainability Tab
The Maintainability tab is used to gather information required to perform a maintainability prediction.
Remarks Tab
The Remarks tab is used to enter remarks and comments regarding the selected part. The Remarks tab includes one field that allows for up to 32 thousand characters. The Remarks tab is a good place to store notes and comments regarding the parts.
NPRD Data Tab
Figure 3 - . Part Properties, NPRD Data Tab
If a category of Other and subcategory of NPRD95 Part is selected for a part in the Parts Table, a tab labeled NPRD Data displays in place of the Prediction Data tab. For more information on entering NPRD95 parts, refer to the “Reliability Prediction” chapter of this manual.
Method Data Tab
The Method Data tab appears only for parts in an assembly for which the current calculation method requires additional information. Method I Case 1 and Method I Case 2 do not require additional information for calculation. Therefore, if Method I Case 1 or Case 2 are selected for an assembly, the Method Data tab does not appear for parts in that assembly. However, all other methods require additional information for calculations. The Method Data tab contains these additional fields of information.
The fields that appear on the Method Data tab are always the same. However, depending on the additional data required by the selected calculation method, only certain fields are active for data entry.
There are three main areas of data on the Method Data tab. These areas are:
Device burn-in data is used for all calculation methods (with the exception of Method I Case 1 and Case 2). This device burn-in data is used in the calculation of the first-year multiplier (which is used to calculate the first year drop out or infant mortality rate). The following fields are active:
Field When Used
Time The device burn-in time in hours. Used for Method 1 Case 3, Method 2 Case L3 and L4, and Method 3 (a), (b), and (c).
Temperature The device burn-in temperature. Used for Method 1 Case 3, Method 2 Case L3 and L4, and Method 3 (a), (b), and (c).
Note: Burn-in data does not affect the predicted steady state failure rate. It impacts the first year multiplier only.
Laboratory Data
Laboratory data is generally used for Method II calculations. The purpose of Method II is to predict unit or device reliability using laboratory data. Method II is calculated as a weighted average of the measured laboratory failure rate and the Parts Count generic failure rate, with the weights determined by the laboratory data. When laboratory tests are very informative, the Method II base failure rate is determined primarily from the laboratory data. When laboratory tests are less informative, the Method II base failure rate is heavily influenced by the Parts Count generic failure rate. The following fields are active:
Field When Used
Number of Failures
The number of failures in the laboratory test. Used for Method II Case L1, L2, L3, and L4.
Number of Test
Devices The number of devices on test. Used for Method II Case L1, L2, L3, and L4.
Test Time The actual time on test in hours. This value is used in combination with test temperature to determine the effective time on test, which is the product of the actual time on test and the laboratory test temperature acceleration factor. Used for Method II Case L1, L2, L3, and L4.
Test Temperature The test temperature in degrees Celsius. This value is used in combination with test time to determine the effective time on test, which is the product of the actual time on test and the laboratory test temperature acceleration factor. Used for Method II Case L1, L2, L3, and L4.
Field Data
Field Data is used for Method III calculations. The purpose of Method III is to predict unit or device reliability using field-tracking data. Method III is calculated as a weighted average of the observed field failure rate and the Parts Count prediction, with the weights determined by the field data. When there is a large number of total operating hours for a device or unit during a field tracking study, the Method III failure rate prediction is heavily influenced by the field data. When there is a small number of total operating hours, the Method III failure rate prediction is more heavily influenced by the Parts