SOX supports ASIL decomposition according to ISO26262. An ASIL decomposition can be performed on safety goals and requirements with safety classification.

Safety Goals

The ASIL decomposition of safety goals can be performed in the views "Project Safety Goal", "PSS",
"Model Explorer (Diagrams)" and " Object list".

1. Right-click a safety goal in order to open the context menu shown below.

   Open

   

   Context menu for decomposing a safety goal.

2. Choose Decompose and your desired decomposition level. The context menu shows all possible decompositions. Unless you have already reached the lowest level, you can do further compositions. - The newly created safety goals will be named with prefixes "A_" and "B_", respectively, and will have new safety- and parent safety levels.

   Open

   

   Safety goal decomposition

Safety Classified Requirements

The ASIL decomposition of requirements can be performed in the "Hierarchy", "PSS", "Model
Explorer- (Diagrams)" and "Object list" views.

1. Right-click on a safety classified requirement.

2. Select Decompose followed by a decomposition level. The context menu shows all possible decompositions. Unless you have already reached the lowest level, you can do further compositions. - The newly created safety goals will be named with prefixes "A_" and "B_", respectively, and will have new safety and parent safety levels.

SysML Example

Deleting a Decomposition

1. Right-click on a decomposed requirement or safety goal.

2. Select Decompose > Delete decomposition. A dialog will open, asking you to confirm deletion of the child elements.

3. Click Yes. The "Refactoring" dialog will open.

4. Click Finish.

The decomposition will be deleted.