Safety Integrity Level Specification
AutoFOCUS offers the possibility of assigning SIL/ASIL to the components of its Logical Architecture.
The Safety Integrity Levels can either be assigned to the requirements and propagated to the corresponding components
of the Logical Architecture or the intended Safety Integrity Level can be directly assigned within the Logical Architecture
to the components. The intended and the propagated Safety Integrity Levels can differ.
Therefore they both are shown in the Safety Specification of the components.
The SILs of the logical components are automatically propagated to their children.
Propagated Safety Integrity Level
This section explains how to propagate Safety Integrity Levels from requirements to components of the Logical Architecture in AF3.
Create a Requirement
Before creating Requirements, you have to create a Requirements Analysis node.
Create a new Requirements node by choosing Requirements, in the context menu of the Requirements Analysis node.
Change the name of a Requirements node in the properties view. You also can create multiple requirement nodes with different names to organize your requirements.
Set Safety Property for Requirements
A double-click on the corresponding requirement opens the requirement view.
The Requirement has to be marked as safety relevant by setting Is Safety Requirement in order to prevent activating the safety property unintentionally.
Enable the check box Is Safety Requirement in the General section of a Requirement.
Propagate Requirement's SIL
In the Safety section of the requirement it is possible to choose between different safety standards, types and levels.
After filling out the fields in the Safety section the requirement can be assigned to a logical component. The Safety Relevance has to be set to yes to finish the propagation.
This adds a Safety Specification to the corresponding logical component.
Intended Safety Integrity Level
The intended SIL can be set in the Logical Architecture within the Safety Specification. If the corresponding component does not yet possess a Safety Specification it can be added to it via drag&drop.
A double-click opens the Safety Specification view where the intended SIL can be set. One can also see whether this component already has a propagated SIL. Intended SIL and propagated SIL may differ.