===== Value Type =====

<WRAP center round help 60%>
  - In Unit instance it is not possible to reference an already existing quantityKind
  - How to define literals for enumeration. Presently have used Attributes but not sure how to use it
</WRAP>

Value Types, sometimes referred to as Data Types comes in three different flavors:

  - Primitive (e.g. Real, String, Boolean)
  - Enumeration (e.g. days of week)
  - Structured (e.g. vectors)

We will first address Primitive types

==== Primitive Types ====

There already exist Primitive Types (e.g. Real, Number, String).

To create a custom Value Type typing a property of a block do the following:

Insert Quantity. In Element Properties -> Run States enter relevant information
{{ :bok:eng:mbse:sysml:bbd-ibd:valuetype2.png?300 |}}

Insert Unit. In Element Properties -> Run States enter relevant information. In quantityKind field enter the name of the created Quantity Kind.
{{ :bok:eng:mbse:sysml:bbd-ibd:valuetype3.png?300 |}}

Insert Value Type. In Element Properties -> SysML 1.5 reference the created Quantity Kind and Unit.
{{ :bok:eng:mbse:sysml:bbd-ibd:valuetype4.png?300 |}}

Insert Block. Drag Property to under the created Block. Select Property and then Element Properties -> Property -> Type. Select the Value Type you just created.
{{ :bok:eng:mbse:sysml:bbd-ibd:valuetype5.png?300 |}}

<WRAP center round help 60%>
How to define a probability distribution for the property?
</WRAP>
==== Enumeration ====
<WRAP center round help 60%>
Is Attribute the right feature for Enumeration? How to use it?
</WRAP>

Insert Enumeration to bdd canvas. Right Click -> Features -> Attributes. Add new attributes until list is complete.
{{ :bok:eng:mbse:sysml:bbd-ibd:valuetype7.png?500 |}}
{{ :bok:eng:mbse:sysml:bbd-ibd:valuetype6.png?500 |}}

Insert Block. Drag Property to under the created Block. Select Property and then Element Properties -> Property -> Type. Select the Enumeration you just created.
{{ :bok:eng:mbse:sysml:bbd-ibd:valuetype8.png?500 |}}

==== Structured ====

Structured Value Types are a composite of simple Value Types and therefore you need to have tha simple types already defined. Add a new Value Type and add two Property under the Value Type. In each Property go Element Properties -> Property -> Type. Select the simple Value Type that you created earlier. 
{{ :bok:eng:mbse:sysml:bbd-ibd:valuetype9.png?500 |}}

Insert Block. Drag Property to under the created Block. Select Property and then Element Properties -> Property -> Type. Select the structured Value Type you just created.
{{ :bok:eng:mbse:sysml:bbd-ibd:valuetype10.png?500 |}}

<WRAP center round help 60%>
How to define initial values for structured value types?
</WRAP>