After you Author Requirements in Simulink and create links between design elements and your requirements, Simulink® Requirements™ tracks the links and detects when linked requirements change. Track change information from the Requirements Editor or in the Traceability Matrix. You can then resolve change issues or clear changes that have no impact on the requirement status.
To enable change tracking for requirement links:
Open the Requirements Editor. From your Simulink model, in the Apps tab, click Requirements Manager. In the Requirements tab, click Requirements Editor. Alternatively, at the MATLAB® command prompt, enter:
Open a requirement set.
Ensure that Information > Change Information is selected.
When you enable Change Information, this setting stays enabled even after you close the Requirements Editor.
Alternatively, you can enable change tracking for requirement links from the Requirements Perspective. Right-click an item in the Requirements Perspective and select Change Information.
Requirements can be linked to other types of items. For a full list of linkable items, see Linkable Items. When you change a requirement that is linked to another item, the link is highlighted in the Requirements Editor and Traceability Matrix to indicate that it has a change issue. After you Enable Change Tracking for Requirement Links, you can view the change issues associated with a particular requirement from the Requirements Editor or the Traceability Matrix.
Simulink Requirements only provides change tracking information for unresolved links if the linked requirement is valid. For more information on why a link might become unresolved, see Resolve Links.
In the Requirements Editor, click Show Requirements. The linked requirements with changes are highlighted in red. When you select a requirement, the associated link is also highlighted in red in the Details pane, under Links. To view the change issue, select a requirement, and, under Links, point to the link, then click the link icon () to the right of the linked item.
In the Traceability Matrix, click Highlight Missing Links > Highlight Changed Links to highlight in red the row, column, and cell associated with the linked requirement that was changed. To view changes to the linked requirement in the Requirements Editor, select the cell and, in the dialog box that appears, click the requirement hyperlink next to Source or Destination. To view the change issue, click the link hyperlink next to Link. To learn more about using the Traceability Matrix to find change issues, see View and Clear Change Issues for Links.
The Requirements Editor displays change information, including change issues, for each link. Click Show Links and, in the Details pane, expand Change Information. Simulink Requirements compares the stored timestamp and revision to the current timestamp and revision for the linked requirement. If you change the requirement after you create the link, or after the last time you changed it, then the Requirements Editor indicates a change issue.
You can resolve change issues from the Requirements Editor or the Traceability Matrix. If a change has no impact, you can clear the change issue. The link change information is updated with the current timestamp and revision for the requirement. If the change issue affects the status of your requirements, you can change the model, the requirements, the test cases, or the links themselves to resolve the revision discrepancy, and then clear the issue.
In the Requirements Editor, links with change issues are highlighted in red when Show Links is selected. To clear a change issue, select the link and, in the Details pane, under Change Information, click Clear Issue.
In the Traceability Matrix, you can highlight links with change issues by selecting Highlight Missing Links > Highlight Changed Links. To clear the change issue, select the cell containing the link and, in the toolstrip, click Clear Change Issue.
You can clear change issues for multiple links at a time in the Requirements Editor or in the Traceability Matrix.
In the Requirements Editor, select multiple links by pressing Shift or Ctrl and clicking the links. Right-click one of the selected links and click Clear Issue from the context menu. To clear all change issues for an entire link set, select the link set and, in the Details pane, under Change Information, click Clear All. You can also right-click the link set and select Clear All Change Issues from the context menu.
In the Traceability Matrix, select multiple cells by clicking and dragging, or pressing Shift or Ctrl, click the cells, and click Clear Change Issue in the toolstrip.
When you resolve change issues, it is good practice to add a comment to the link describing the action that you took. Each link has a Comments property. When you clear a change issue in either the Requirements Editor or Traceability Matrix, a dialog box appears and you are prompted to add a comment.
To add an additional comment:
In the Requirements Editor, click Show Links.
Select the link.
In the Details pane, under Comments, click Add Comment.
Change tracking information is automatically updated in the Requirements Editor, but it can also be manually refreshed. To refresh the change tracking information:
In the Requirements Editor, click Refresh.
In the Traceability Matrix, click Update.
In the Traceability Matrix, change tracking information must be refreshed manually.