Which sequence best represents the typical phases of the functional safety lifecycle?

Which sequence best represents the typical phases of the functional safety lifecycle?

• A. Concept; safety requirements; implementation; production; operation; service; modification; decommissioning.
• B. Concept; overall safety requirements; implementation; production; operation; service; modification; decommissioning.
• C. Concept; overall safety requirements; detailed safety requirements; implementation; production; operation; service; modification; decommissioning.
• D. Concept; overall safety requirements; detailed safety requirements; development; production; operation; service; modification; decommissioning.

Answer: (C)

The main idea is that a functional safety lifecycle moves from defining broad safety goals to refining them into concrete, testable requirements before actually building the system, and then carries those requirements through production, operation, and end-of-life activities. First comes the concept phase, where safety goals are established. Next you derive overall safety requirements that capture system-wide objectives. Then you translate those into detailed safety requirements for the components, so every part has precise, verifiable criteria. This refinement is essential because you can only implement and verify safety once you have specifics you can design to and test against. After the detailed requirements are in place, the implementation phase realiz es the design in hardware and software, guided by those exact requirements. Once implemented, production ensures the product is manufactured in accordance with the design. The lifecycle then proceeds through operation and service (maintenance), with subsequent modification for changes and decommissioning at end of life. Other sequences either skip the detailed safety requirements or use a different term for the later phase, which can blur the necessary progression from broad goals to precise, testable requirements before implementation.

The main idea is that a functional safety lifecycle moves from defining broad safety goals to refining them into concrete, testable requirements before actually building the system, and then carries those requirements through production, operation, and end-of-life activities. First comes the concept phase, where safety goals are established. Next you derive overall safety requirements that capture system-wide objectives. Then you translate those into detailed safety requirements for the components, so every part has precise, verifiable criteria. This refinement is essential because you can only implement and verify safety once you have specifics you can design to and test against.

After the detailed requirements are in place, the implementation phase realiz es the design in hardware and software, guided by those exact requirements. Once implemented, production ensures the product is manufactured in accordance with the design. The lifecycle then proceeds through operation and service (maintenance), with subsequent modification for changes and decommissioning at end of life.

Other sequences either skip the detailed safety requirements or use a different term for the later phase, which can blur the necessary progression from broad goals to precise, testable requirements before implementation.