Unit Settings

ReliaSoft databases are pre-configured with a set of units for use with any analysis in any project within the database. The conversion factors are predefined, allowing you to easily express results in terms of other units. For example, you can enter data into a Weibull++ data sheet in terms of hours and then obtain results from the QCP in terms of years. Similarly, in RCM++ or BlockSim, you can define the duration of a maintenance task in terms of hours and specify the total operating time of a system in terms of months. In MPC, the units can be used to define task intervals.

IMPORTANT: Making changes to the existing units can have implications for all analyses throughout the database; therefore, it is best to set up units once, upon creation of the database.

To define units, choose File > Manage Database > Unit Settings. (In a secure database, this is available only to users with the "Manage other database settings" permission.)

If you're working in Weibull++, the Warranty Units tab will be available. It allows you to specify which of the configurable database units are equivalent to the built-in (not configurable) "warranty time units" used in some warranty folio formats. For details, see Manage Warranty Units in the Weibull++ documentation.

Setting SBU Equivalencies

The conversion factor of a unit is defined in relation to a system base unit (SBU). A base unit is a standard unit of measurement upon which other units can be based. Base units always have a conversion factor of 1. All other related units are converted back to the base unit.

For example, say that we choose kilograms (kg) as our SBU for mass. The conversion factor of related units, such as pounds (lb) and metric tons (T), must be entered in terms of the SBU:

Unit	SBU Equivalency (using kg as the base unit)
1 kg	1 kg
1 lb	0.4536 kg
1 T	1000 kg

Similarly, if we change the base unit to pounds (lb), the conversion factors must reflect the change:

Unit	SBU Equivalency (using lb as the base unit)
1 kg	2.2046 lb
1 lb	1 lb
1 T	2204.62 lb

By default, ReliaSoft databases use hours (hr) as the SBU for time, and miles (mi) as the SBU for length. To ensure that you obtain correct results when converting units, it is recommended that you set an SBU for each type of measurement (e.g., time, length, frequency, force, etc.) and define the conversion factors of all other units in terms of the relevant SBU.

Changing the Default Unit

You can set any unit as the default by selecting it in the Use as Default column. The software will automatically use the new default unit when you create a new analysis or resource in any project in the database. The change will not affect existing analyses and resources.

Creating and Deleting Units

To add a new unit, click the Add button below the table and follow the on-screen prompts to create the unit. The wizard will automatically calculate and apply the appropriate SBU equivalency based on your inputs.

To delete a unit, click the Delete button below the table. There is no undo for delete.

Editing Existing Units

Click a cell to edit a unit’s name, abbreviation, SBU equivalency and category. To apply your changes, click the Save button at the bottom of the window.

Note that if you will be using the usage format of the Weibull++ warranty folio, only the units assigned to the Usage category will be available for those analyses; units assigned in the Time category are not available in the warranty usage format.

Built-in Find/Filter, Configuration and Grouping Tools

You can move a unit up or down its current position by dragging the row to the desired position, or by selecting it and using the Move Up or Move Down buttons.

To show more tools, right-click any column heading. The window offers the same filter, column configuration and grouping tools that are built in to other utilities that use a similar grid (e.g., the Resource Manager). For details about each feature, see: