A Safety Requirement Diagram displays safety goals, safety requirements and their relations. The main purpose of this diagram is to create requirements that cover the safety goals defined in HARA. In this chapter, you will learn how to derive safety requirements using the Safety Requirement Diagram and how to assign ASIL values.
Safety Requirements are derived from Safety Goals defined in a HARA Table. You can use the Safety Requirement Diagram to derive four types of Safety Requirements: Functional Safety Requirements, Technical Safety Requirements, Software Safety Requirements, and Hardware Safety Requirements.
To derive a Safety Requirement
Create the Safety Requirement you want to derive by clicking it in the diagram palette and clicking an empty space on the diagram pane.
You can create four types of Safety Requirements: Functional Safety Requirements, Technical Safety Requirements, Software Safety Requirements, and Hardware Safety Requirements. |
After you derive a Safety Requirement, the ASIL value is automatically determined by the Safety Goal you have derived the Requirement from. If a Safety Requirement is derived from more than one safety goal or Safety Requirement, a higher ASIL value is set. However, you can specify a different ASIL value than the one defined by a Derive relationship.
To change the ASIL value