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SysML Block Definition Toolbox

When you are constructing SysML models, you can populate the Block Definition diagrams using the icons on the SysML Block Definition pages of the Diagram Toolbox.

You can also generate Property elements on the Block, based on the Association relationships created for the Block element. These Properties (or Parts) are initially created in the Project Browser, but you can quickly render them on the Internal Block diagram for the Block.

Access Diagram | Toolbox : More Tools | SysML 1.3 | SysML 1.3 Block Definition

SysML Block Definition Objects




Defines a composite system entity in SysML.


Represents a user that interacts with one or more SysML systems.

Interface Block

A specialized kind of block that has no behaviors or internal parts, which is used to type Proxy Ports.

Constraint Block

Defines a composite constraint as a system of parametric equations.


Defines a SysML quantity, expressed as a measurable dimension with specific units.


Defines a data type as a set of symbols or values.


Defines an element that describes a specification of an interaction point with properties and methods.


Defines a SysML message, containing attributes, exchanged between system blocks in an interaction.


Represents a standard unit of measure in SysML.


Identifies a measurable quantity in SysML.


Describes the decomposition of a SysML Block in the context of its whole, using instances of reusable SysML Blocks.

Flow Property

Creates a single kind of Flow element that can flow to or from a block.

Directed Feature

Generates an operation if dropped on a Block, or a DirectedFeature (Property) element if dropped on the diagram, both of which indicate that the associated Block either owns (provided) the feature, uses (required) the feature owned by another Block, or both (providedrequired).

The direction value is defined in the 'SysML1.n' page of the element 'Properties' dialog, or the 'Tagged Values' page of the operation 'Properties' dialog.


Describes a structural interaction point of a SysML Block, which in turn connects interacting parts of a block.

Proxy Port

Exposes features of the owning Block or its internal parts.

Full Port

Specifies an element of the system separate from the owning Block or its internal parts.

SysML Block Definition Relationships



Item Flow

Specifies the items that flow across a connector in an interaction point. Used in the same way as UML Information Flows.

See Using Information Flows


Establishes a traceable relationship describing how one element is dependant upon another.


Describes an element as a specialized descendant of another element, containing additional properties and behavior.


Graphically displays ownership of one element within a parent element.

Part Association

Describes the characteristics of a connection between a SysML Block and its internal parts, such as the multiplicity and type.

Reference Association

Describes the characteristics of a connection between separate SysML Blocks, such as the multiplicity and type.

Shared Association

Describes the characteristics of a common connection between SysML Blocks, such as the multiplicity and type.


Connects model elements to formalize a refinement of behavior, structure, constraints or design expectations.

SysML Patterns



Composite Block

A pattern that creates a Composite Block, made up of Blocks related by Aggregation relationships.

Block with Parts

A pattern that creates a Composite Block made up of nested parts.

SysML Deprecated



Flow Port

Describes what flows in and out of interacting SysML Blocks.

See Show Direction on SysML 1.3 Ports

Flow Specification

Defines a set of flow properties that correspond to individual pieces of a common interaction point.

See Show Direction on SysML 1.3 Ports

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