Reliability HotWire

Issue 101, July 2009

Tool Tips

* How can I use the Monte Carlo Simulation utility in Weibull++ for risk analysis, probabilistic design and quality control?

The Monte Carlo simulation tool in Weibull++ is a flexible utility that you can use to automatically generate a data set for a specified distribution and parameters. You can also use this tool for relationship-based simulations that are useful for risk analysis, probabilistic design and quality control.

Specifically, the Monte Carlo utility’s "User Defined" distribution feature allows you to specify an equation relating different random variables. You can then determine the joint pdf for the simulated data set. This type of simulation has many applications in probabilistic design, risk analysis, quality control, etc.

For example, suppose that you have a hinge containing four components: A, B, C and D. You have information about the range of widths that have been observed for the components and you need to estimate the number of times that the combined widths of A, B and C will be greater than D.

Diagram of Hinge

You can enter the component measurements from several hinges into separate data sheets in a Weibull++ Folio. Next, you can generate two sets of Monte Carlo data: the first can be created by using the "User Defined" distribution option to combine the distributions data from Components A, B and C (as shown below) and the second can be created based on the data from Component D.

You open the Monte Carlo window by choosing Tools > Generate Monte Carlo Data. Then choose User Defined from the Distribution drop-down list and enter the equation in the Parameters area.

Monte Carlo Window

After generating the Monte Carlo data sets, you can use the Comparison Wizard to estimate the number of times A+B+C will be greater than D.

After generating the Folios, you open the Comparison Wizard by choosing Tools > Tests of Comparison. You can then select the appropriate Data Sheets for comparison.

Comparison Wizard

For a full summary of this example, refer to the Hinge (Simulation and Test of Comparison).rwp file, located in the Examples\Other Tools\Simulation folder within the application directory (e.g. C:\Program Files\ReliaSoft\Weibull7\Examples\Other Tools\Simulation).

For more information about using the Monte Carlo simulation tool, refer to the Weibull++ User’s Guide.

* How do I configure my software to display the interface in another language?

Several of ReliaSoft’s products (Weibull++, ALTA, DOE++, BlockSim, RCM++ and Xfmea) provide the software interface translated to other languages in addition to English. The "Multi-Language Support for Reliability Software from ReliaSoft" page,, provides the most up-to-date information about which languages are supported in each product. (Note that additional language support will be added in future releases.)

When you install the ReliaSoft product, it will automatically detect the version of Windows® you are using and enable the matching language if it is available. For example, if you are using the French version of Windows and the ReliaSoft product is available with a French interface, the French interface will automatically be enabled by default. (If you are using a language that is not yet available for the ReliaSoft product, the English language interface will be enabled by default.)

You can change the interface language from with the ReliaSoft product interface by choosing File > User Setup and then clicking the Other page, such as shown in the Weibull++ User Setup window below. Use the Language field to select the desired language.

Weibull++ User Setup Other Page

Click OK to save the change. Note that you must close the application and restart it for the interface language change to take effect.

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