A Value Type is defined as a stereotype of UML Data Type to establish a more neutral term for system values that may never be given a concrete data representation. A Value Type adds an ability to carry a units of measure of a Quantity Kind associated with the value.

Use the QUDV model library to find all standard value types.


When specifying the Value Type for a Value Property, you can select one of the following:

  • Unitless Value Type.
  • Value Type with specified unit.

Look at the table below to see the differences.

If you want to specify the Value Type for a Value Property, follow the procedures in the Using Units page.

Value TypeName constructionPurposeExample
UnitlessQuantity name, e.g. distance.Use this to create a general-purpose model. Instance Specifications and its Slots can contain different units of the same Block.

With specified unitsQuantity and unit names, e.g. distance[metre].Use this to create a specific-purpose model. Instance Specifications and its Slots can contain the same units of the same Block.