Reliability HotWire

Reliability HotWire

Issue 125, July 2011

Tool Tips

*How should I use the Auto Group Data tool in Weibull++ and ALTA?

The Auto Group Data tool in Weibull++ and ALTA automatically groups together data points with the same failure/suspension times. Grouping your data significantly speeds up calculations when you have a very large data set. To group your data, choose Data > Auto Group Current Data or click the Auto Group Data icon.

Auto Group Data icon

In addition to grouping exactly identical values, you also have the option to round the values in the data sheet (e.g., to the nearest whole number or to the nearest multiple of 10) and then group them. This can be useful when you need to set the accuracy of your computations. For example, a recorded observation of 509.71 cycles may be known to be accurate only when rounded to the nearest whole number. Note that if you use subset IDs, the utility considers the values (or rounded values) to be identical only if they have identical subset IDs, as shown next.

Rounded data points
Data points rounded to the nearest whole number and then grouped

*How do I use parts from PartLibraries.org in Lambda Predict?

Lambda Predict’s library functionality helps you to share knowledge, ensure consistency and save time on data entry. In this tip, we focus on how to use parts from the libraries in the website portal at PartLibraries.org in your prediction. These techniques are also effective for using parts in local libraries (i.e., in the sample library files shipped with the application and in the custom library files that you create) and parts defined in existing analyses.

ReliaSoft’s PartLibraries.org facilitates the collection and dissemination of component data for use in standards-based reliability predictions and other reliability analyses. For information about the data it contains and about free and subscription-based access, please visit http://Predict.ReliaSoft.com/part_libraries.htm.

You can use the library functionality:

  • To specify properties for components you are currently adding.
    • The Add Existing Components window allows you to search for existing components in the current prediction, the current database, other databases, local library files or PartLibraries.org, and then add selected components to your system hierarchy.

      Add Existing Components Window (System Hierarchy > Add [Next/Same] Level Item > Existing Components)

    • The Search PartLibraries.org window offers more full-featured search capabilities for the database at PartLibraries.org. To use the window, click Update Search Parameters to update the available search terms in the Supplier, Generic Category and Category drop-down lists. This will ensure that if any new search terms have been added to PartLibraries.org since you last used this window, they will be available for your use. Specify your search criteria in the panel on the left and click Search.

      Add Existing Components Window (System Hierarchy > Add [Next/Same] Level Item > Existing Components)

  • To specify properties for components you have already added. You can select a single component or an entire system in your system hierarchy and search the database at PartLibraries.org for matching parts based on the category and part number for each component within the selection. In either case, when matches are found, four general properties (Name, Description, Supplier and Notes) and all physical parameters are taken from the part(s) in the database and applied to the matching component in your analysis. The following commands are used:
    • Tools > Update Component from PartLibraries.org
    • Tools > Update Hierarchy from PartLibraries.org
  • When importing components from an Excel or delimited text file. As noted in Reliability HotWire Issue 114, when you are importing components via the Import Wizard, the Part Number Lookup area allows you to compare the part numbers imported from the Excel or delimited text file with part numbers in one or more libraries, in the current project and/or in the database at PartLibraries.org. If a match is found, any additional part data not specified in the Excel or text file will be taken from that matching part.

For more detailed instructions on using the library capabilities of this software, please refer to the Lambda Predict 3 User’s Guide.