ISA/IEC 62443 Cybersecurity Fundamentals Specialist — Question 88

In terms of availability requirements, how do IACS and IT differ?

Answer options

• A. IACS tolerates occasional failures while IT does not.
• B. Rebooting is never acceptable in IT but tolerated in IACS.
• C. Both IACS and IT have the same availability requirements.
• D. Continuous operation is expected in IT while scheduled operation is sufficient for IACS.

Correct answer: D

Explanation

The correct answer is D because IT systems are designed for continuous availability, while IACS can operate with scheduled downtimes. Options A and B incorrectly generalize the failure tolerance and reboot policies for IT, while C falsely claims that both systems have the same availability standards.