What should modifications or changes during the Factory Acceptance Test (FAT) involve?

• A. No modifications allowed
• B. Allowed with proper documentation
• C. Allowed subject to a safety analysis
• D. Allowed if approved before plant startup

Answer: (C)

Modifications or changes during the Factory Acceptance Test (FAT) should ideally involve a thorough safety analysis to ensure that any alterations do not introduce risks to the safety of the system. This emphasizes the importance of maintaining safety integrity when making adjustments. A safety analysis allows for the evaluation of potential impacts from changes, ensuring that risk assessments are made and any safety implications are addressed beforehand.

Conducting a safety analysis keeps the overall system reliability intact and fosters an environment where changes are managed systematically. This approach helps to safeguard compliance with functional safety standards, ensuring that all safety requirements are met even during the testing phase.

While documentation and prior approval may also be part of the process, the key focus during FAT is to ensure that any modifications maintain the overall safety assurance through careful evaluation. Therefore, the necessity of a safety analysis as part of making modifications highlights a proactive approach to risk management in functional safety practices.