Sequence Diagram

Innoslate's ‘Sequence Diagram’ is used to represent the sequential message flow (Input/Output entities) between Lifelines (Asset entities).

Using Sequence Diagrams

The ‘Sequence Diagram’ is used to represent the sequential message flow (Input/Output entities) between Lifelines (Asset entities). The diagram is represented in standard SysML and LML notation and is bidirectionally compatible with the action diagram (modifications in the ‘Action Diagram’ automatically change the ‘Sequence Diagram’ and vice versa). 

Creating Sequence Diagrams

Within the ‘Diagrams Dashboard,’ users can create a new diagram by clicking the ‘ Create Diagram’ button in the top right corner of the page.

Clicking the ‘ Create Diagram’ button will open the Create Diagram dialog where you will be directed through the process of creating a new diagram.

Create a Sequence Diagram

1. Choose Which Type of Diagram to Create
   In step 1, select ‘Sequence Diagram,’ under ‘SysML,’ as your diagram type.
   
                

    

   Click the ‘Next’ button.

                
   
   
2. Specify New Root Action Information
   In step 2, you will be prompted to input a diagram ‘Name,’ ‘Number’ (optional), and ‘Description’ (optional). Then, click the ‘Finish’ button to save and automatically open your new Sequence Diagram.
   
                

Sequence Diagram Constructs

This section defines the building blocks of a ‘Sequence Diagram’ in Innoslate. The ‘Sequence Diagram’ supports two unique diagram constructs: a ‘Lifeline’ and a ‘Message.’ Each diagram construct is described in more detail below:

• Lifeline

  This construct is used to capture the physical components of a system that are interacting with each other.

  In the system model, an Asset entity is used to represent a ‘Lifeline’ construct. Innoslate’s default database schema includes labels to specify the type of this Asset entity as a(n) Architecture, Context, Environment, External System, Facility, Infrastructure, Materiale, Organization, Package, Personnel, Segment, Service, Subsystem, and/or System.

  In the diagram, this construct is represented as a rectangle shape containing the name of the ‘Lifeline’ with a dashed vertical line centered below it.

  

• Message

  This construct is used to capture any interactions made between ‘Lifeline’ constructs.

  In the system model, an Action entity is used to represent a ‘Message’ construct.  ‘Lifelines’ perform these Actions, which act as the processes that send and receive Input/Outputs between the ‘Lifelines’.

  In the diagram, this construct is represented as an arrow pointing to a destination ‘Lifeline’ which originates from a source ‘Lifeline,’ and a line label containing the name of the ‘Message.’

  

Adding a Lifeline

A ‘Lifeline’ construct can be added to a ‘Sequence Diagram’ via drag-and-drop.

1. Within a ‘Sequence Diagram’, click the ‘Lifeline (Asset)’ icon in the ‘New’ tab of the left sidebar and continue to hold down the left mouse button.

   
   
   

2. Drag the ‘Lifeline (Asset)’ icon over to the adjacent diagram canvas.

   
   
   

3. Release the left mouse button while over the diagram canvas to drop the new ‘Lifeline’ and add it to the diagram. The ‘Lifeline’ will automatically snap to the position at the top of the diagram, ordered by number.

   
   

    

   Notice the ‘Lifeline’ stays selected once it has been dropped. Since it is selected, the toolbar changes to include buttons for functions that can be used on the construct. The sidebar also changes to include additional ‘Metadata,’ ‘Attributes,’ and ‘Relationships’ tabs.

4. Once added to the diagram, enter a meaningful ‘Name’ for your new ‘Lifeline’ via the ‘Attributes’ tab of the left sidebar (focused automatically for convenience).

   
   
   

5. Click the ‘Save’ button located on the toolbar to persist your changes to your project’s database.

   

* Note: The above process describes using the ‘New’ tab of the left sidebar, which automatically generates a new entity to represent each new diagram construct. If you would like to reuse existing entities from your database to represent a new construct, use the ‘Existing’ tab instead.

Adding a Message

A ‘Message’ construct can be added to a ‘Sequence Diagram’ via drag-and-drop.

1. Within a ‘Sequence Diagram’, select the source ‘Lifeline’ where you would like the ‘Message’ to originate from.

   
   
   

2. Click the green circle and continue to hold down the left mouse button.

   
   
   

3. Drag the green circle to the dashed line below the destination ‘Lifeline’ of your choice.

   
   
   

4. When the dashed line below the destination ‘Lifeline’ highlights green, release the left mouse button to drop the new ‘Message’ and add it to the diagram.

   
   

    

   Notice the ‘Message’ stays selected once it has been dropped. Since it is selected, the toolbar changes to include buttons for functions that can be used on the construct. The sidebar also changes to include additional ‘Metadata,’ ‘Attributes,’ and ‘Relationships’ tabs.

5. Once added to the diagram, select your new ‘Message’ and enter a meaningful ‘Name’ for your ‘Message’ via the ‘Attributes’ tab of the left sidebar.

   
   
   

6. Click the ‘Save’ button located on the toolbar to persist your changes to your project’s database.

   
7. When dealing with mutiple messages and you want to place the new lifeline in a particular order, note when dragging the message you can select the desired spot on the lifeline with the dashes.
    

Note: The above process describes using the ‘New’ tab of the left sidebar, which automatically generates a new entity to represent each new diagram construct. If you would like to reuse existing entities from your database to represent a new construct, use the ‘Existing’ tab instead.

Removing a Construct

A construct can be easily removed from a ‘Sequence Diagram.’

1. Within a ‘Sequence Diagram,’ select the construct you wish to remove. This will make the toolbar appear with applicable functions which can be used on the selected construct.
   
   
   
   
2. Click the  ‘Remove’ button to remove the construct from the diagram (as the default action). 
   
   

   * Note: The  ‘Remove’ button also includes a drop-down menu where you can select ‘Delete from Database’ or the default option of ‘Remove from Diagram.’

Tutorial Video

To continue learning about SysML Diagrams, Click Here.

(Next Article: Sequence Diagram Modifications & Settings)