Class Diagram Constructs

Last modified on March 22nd, 2018.


The 'Class Diagram' supports six unique diagram constructs: a 'Class,' an 'Operation,' an 'Attribute,' an 'Input Parameter,' a 'Return Type,' and a 'Logical Connection.' Each diagram construct is described in more detail below:

Class Diagram Constructs

Last modified on March 22nd, 2018. 


The ‘Class Diagram’ supports six unique diagram constructs: a ‘Class,’ an ‘Operation,’ an ‘Attribute,’ an ‘Input Parameter,’ a ‘Return Type,’ and a ‘Logical Connection.’ Each diagram construct is described in more detail below:

  • Class

    In the system model, an Asset entity is used to represent a ‘Class’ construct. A ‘Class’ must be added to the diagram first before any of the other constructs can be added. In the diagram, this construct is represented as a rounded box which contains the name of the ‘Class.’

  • Operation

    In the system model, an Action entity is used to represent an ‘Operation’ construct. A ‘Class’ must be added to the diagram first before this construct can be added. In the diagram, this construct is represented as a line of text containing the name of the ‘Operation’ in an “Operations” section of the ‘Class.’

  • Attribute

    In the system model, a Characteristic entity is used to represent an ‘Attribute’ construct. A ‘Class’ must be added to the diagram first before this construct can be added. In the diagram, this construct is represented as a line of text containing the name of the ‘Attribute,’ a semicolon, and the units of the ‘Attribute’ in an “Attributes” section of the ‘Class.’

  • Input Parameter

    In the system model, an Input/Output entity is used to represent a ‘Input Parameter’ construct. An ‘Operation’ must first be added to a ‘Class’ in the diagram before this construct can be added. In the diagram, this construct is represented as a line of text containing the units of the ‘Input Parameter’ in parenthesis.

  • Return Type

    In the system model, an Input/Output entity is used to represent a ‘Return Type’ construct. An ‘Operation’ must first be added to a ‘Class’ in the diagram before this construct can be added. In the diagram, this construct is represented as a semicolon and a line of text containing the units of the ‘Return Type.’

  • Logical Connection

    In the system model, a Logical entity is used to represent a ‘Logical Connection’ construct. At least two ‘Class’ constructs must be added to the diagram first before a ‘Logical Connection’ can be added. In the diagram, this construct is represented as a solid line connecting two ‘Class’ constructs and a line label containing the name of the ‘Logical Connection.’