Track Changes in Safety Analysis Manager Fault Tree Documents

R2026b

Since R2026b

If you have a Requirements Toolbox™ license and your files are in a project, you can create links that connect events, gates, and failure models in Safety Analysis Manager fault tree documents to external artifacts such as requirements, test cases, or model elements. When these linked artifacts change, you can use change tracking to identify which fault tree elements are affected, then accept the changes to update the baseline.

To learn how to create links to events and gates before tracking changes, see Link Safety Analysis Manager Fault Tree Artifacts to Requirements, Tests, and Faults.

Establish a Baseline and Detect Changes

To detect changes to Requirements Toolbox links and linked artifacts, you must open the project that contains the files and open the fault tree document. After opening the project and the files, you establish a baseline. The Safety Analysis Manager saves the baseline in the derived folder of the project. When you make changes to the links or linked artifacts, the Safety Analysis Manager compares the changes to the baseline.

Establish a Baseline

The Safety Analysis Manager establishes baselines for the links and linked artifacts in the fault tree document when you:

• Manually accept changes by clicking Accept All in the Analyze Changes section of the toolstrip. The Safety Analysis Manager establishes a new baseline state for each artifact in the fault tree document.

• Open or save the fault tree document while the project is open. When you open or save the fault tree document, the Safety Analysis Manager creates new baselines for artifacts that do not have a baseline. For example, if you open a fault tree document and add three events, you can establish baselines for the new events by saving the fault tree document.

The Safety Analysis Manager does not establish baselines when:

• The changed files and artifacts are not on the project path.

• You add events, gates, or failure models to the fault tree document and save the document while the project is closed.

• You add an open fault tree document to the project. To establish the baseline, close the fault tree document, add it to the project, then reopen it.

Creating a baseline overwrites the previous baseline.

Detect Changes from Baselines

After establishing the baseline, you can detect changes to the links or linked artifacts. To detect the changes, in the Analyze Changes section, click Detect, or use the detectChanges function.

The Safety Analysis Manager detects changes when you:

• Create a link to an event, gate, or failure model and save the link set.

• Delete a link from an event, gate, or failure model and save the link set.

• Update the properties of a link to an event, gate, or failure model and save the link set.

• Change a linked artifact, such as a requirement, test case, or model element, and save the file. For a complete list of linkable artifacts, see Linkable Items (Requirements Toolbox). If the artifact is in a Simulink^® model, the Safety Analysis Manager only indicates that the model changed, and does not identify the specific changed artifact.

  Note

  If you save the Simulink model and detect changes, the fault tree document reports changes to linked artifacts in the Simulink model, even if those artifacts are unchanged.

• Change and save a dependent file associated with a linked artifact and save the file. For example, if you link a test case that has a model under test to an event, then save the model, the event indicates a change.

• Save the Simulink model that contains an artifact that links to an event, gate, or failure model.

The fault tree document adds a detected changes badge to linked events, gates, and failure models if it detects a change.

View Affected Artifacts and Accept Changes

The detected changes badge can represent more than one detected change. You can navigate to the source of the change from the fault tree document by pointing to the badge and clicking the source name. You can also programmatically access the change information by using the getChanges function to retrieve the ChangeInformation objects of the detected changes.

To view a list of the changes in the fault tree document, event, gate, or failure model, in the Properties pane, in either the Fault Tree Document, Event, Gate, or Failure Model tabs, expand the Changes section.

You can accept a single change or all of the changes in a fault tree, event, gate, or failure model. To accept individual changes,

• Point to the right of the event, gate, failure model, or individual change, and click the green check mark .

• Use the accept function on the ChangeInformation object.

To accept all changes in the fault tree document:

• In the Analyze Changes section, click Accept All.

• Use the acceptAllChanges function.

Accepting a change updates the baseline.

If the change is caused by creating a link, you cannot accept the change individually. You must accept all of the changes in the event, gate, failure model, or fault tree document that contains the change.

Track Changes in Safety Analysis Manager Fault Tree Document Example

This example shows how to detect changes to links and linked artifacts to a Safety Analysis Manager fault tree document. In this example, the fault tree document links to an architecture model of an aircraft elevator. The model is an architectural representation of the plant model in the Verify Fault Detection Logic in Aircraft Elevator Control System example.

Open the Project, Model, and Fault Tree Document

Open the project, aircraftElevatorFaultTreeProject.

openProject("aircraftElevatorFaultTreeProject");

This example contains an architecture model, aircraftElevatorPlantArchitecture, and a fault tree document, elevatorFaultTree.mldatx. The architecture model contains faults, and the faults link to the events in the fault tree document by using Requirements Toolbox™ links. Open the model and the fault tree document.

open_system("aircraftElevatorPlantArchitecture");
safetyAnalysisMgr.openDocument("elevatorFaultTree.mldatx");

Open the Safety Analysis Manager to view the fault tree document and the links.

safetyAnalysisManager

To represent the failure of the aircraft elevator, the fault tree document contains three fault trees:

• Hydraulic Failure — The fault tree associated with the hydraulic system.

• Position Failure — The fault tree associated with the position sensors.

• Elevator Failure — The fault tree associated with the failure of the aircraft elevator.

In the Safety Analysis Manager, click Detect. There are no changes in the document. Click Accept All to establish a new baseline.

Change the Fault Property

The architecture model has seven faults, and each fault links to a basic event. The faults assigned to the hydraulic system link to the events in the Hydraulic Failure fault tree, and the faults assigned to the position sensors link to the events in the Position Failure fault tree. Adjusting the properties of one fault results in a detected change for the artifact linked to the fault. In this example, delete one fault, save the changes, and detect the changes from the fault tree:

1. In the aircraftElevatorPlantArchitecture model, open the Fault Analyzer app. In the Apps tab, click Fault Analyzer. The Fault Table pane opens.

2. In the Fault Table pane, in the Fault tab, expand the Measured Left Inner Actuator positions/Inport/1 model element to view the fault on the input port of the Measured Left Inner Actuator positions component, Left_Inner_Actuator_fault.

3. Right-click the fault and click Delete.

4. In the Fault Analyzer tab, in the File section, click Save All > Save Only Fault Artifacts.

5. In the elevatorFaultTree.mldatx fault tree document, detect the changes. In the Analyze Changes section, click Detect.

The fault tree document detects that the linked fault is deleted in the Left Inner Actuator Failure event. To view the detected change, in the Opened Documents pane, expand elevatorFaultTree and select the Position Failure fault tree.

The other basic events are unaffected.