Item

Component or set of components that implements a function at the vehicle level.

Item Block

An Item Block is a part of the system that needs to be assessed with a TARA process. An Item Block is a SysML Block.

Members

Elements that are within the item block.

Boundary Members

Elements and/or ports that connect the item with other elements.

Creating an Item

To create an Item

  1. In the Containment tree, right-click Items & Assets Definition and select Create Element.



  2. Do one of the following:
    • In the dialog, expand ISO 21434 and select Single Block Item.



    • In the search tab, type the keyword item and then select Single Block Item.



  3. Name the created Item in the Containment tree. The Item has the prefix IT, which denotes that the created element is an Item; the number 1 indicates that it is the first Item created.

After creating an asset, it is beneficial to find its location in the model tree by performing one of the following:

  • Right-click the asset, and, from the shortcut menu, choose the Select in Containment Tree command.
  • Select the asset and press Alt+B.

Creating an Item Table

If you create a new project using the ISO 21434 Project template, then an Item Table already exists in the 2.1 Items & Assets Definition package.


To create an Item Table

  1. In the Containment tree, right-click Items & Assets Definition and select Create Diagram.



  2. Do one of the following:
    • In the dialog, expand ISO 21434 and select Item Table.



    • In the search tab, type the keyword item and then select Item Table.



      The Item Table is now displayed in the diagram pane of the modeling tool.

Adding an Item to the Item Table

To add a new Item to the Item Table

  1. In the Item Table, click Add New. A row is added to the Item table, which shows the new Item.



  2.  In the newly created Item's row and in the Name column, double-click the designated cell to name the Item.



To add an existing Item in the Item Table

  1. In the Item Table, click Add Existing.



  2. From the Select Single Block Item dialog, select the required Item. A row is added to the Item table, which shows the existing Item.



  3. In the existing Item's row and in the Name column, double-click the designated cell to rename the Item.

Assigning SysML Block as an Item Block

To assign SysML Block as an Item Block

  • Double-click the designated cell in the Item's row and the Item Block column. In the drop-down list, select the Item Block.



    The added Item Block is now displayed in the Item Table.

  • You can also drag and drop the SysML Block from the Containment tree to the Item Table.
  • Once you declare a SysML Block as an Item Block, a legend appears at the top left corner of the element.

Item Table Example

In an Item Table, Members and Boundary Members columns are automatically filled based on the Item Block definition.

References