In a multi-entity BES environment, what practice helps ensure synchronous time-dependent actions?

• A. Independent local clocks in each entity
• B. Shared time standards across entities
• C. Synchronized clocks without shared standards
• D. Use of a single, central time-source and synchronized clocks across entities

Answer: (D)

Maintaining a single reference time across the BES ensures time-dependent actions across entities occur synchronously. In a multi-entity environment, devices need to timestamp events and coordinate actions precisely. If each entity uses its own clock, those clocks can drift apart, leading to misordered events and miscoordinated protection or control actions. A central time source provides a common reference, and when every device’s clock is synchronized to that source, all time stamps line up and actions happen in the intended sequence. This makes post-event analysis accurate and ensures real-time operations remain coordinated across entities. Using independent local clocks, or relying only on shared standards without true synchronization, can still result in skew between devices, while synchronized clocks without a central reference may not stay aligned to a common baseline. Therefore, the combination of a single central time source with synchronized clocks across entities best preserves synchronous timing across the BES.