Prior to implementing a planned BES modification that would change the restoration plan, within how many days must the Transmission Operator update the restoration plan?

• A. 30 calendar days
• B. 60 calendar days
• C. 90 calendar days
• D. 120 calendar days

Answer: (C)

The key idea is that changes to how the BES is restored require advance coordination. When planning a modification that would change the restoration plan, the Transmission Operator must update the restoration plan at least ninety calendar days before implementing the modification. This lead time gives reliability coordinators, neighboring entities, and internal teams enough opportunity to review the proposed changes, adjust procedures, align resource assumptions, and conduct any necessary testing or coordination activities to keep restoration efforts reliable.

If the update were requested sooner (shorter than ninety days), there wouldn’t be enough time for thorough review and coordination. A much longer lead time (like one hundred twenty days) isn’t the requirement and could unnecessarily delay the modification, while shorter lead times would undermine coordination and reliability. The ninety-day interval strikes the balance needed for proper preparation before changing the restoration approach.