IEEE P859/D2, Nov 2017 is an approved draft standard focused on terms for reporting and analyzing outage occurrences and outage states of electrical transmission facilities. It is relevant to power-system professionals who need a consistent vocabulary for documenting interruptions, classifying operating conditions, and comparing outage data across transmission assets. By tightening how events are described, IEEE P859/D2, Nov 2017 helps support clearer communication, more reliable records, and better alignment between engineering, operations, and analysis work.

Overview of IEEE P859/D2, Nov 2017

This draft standard addresses the terminology used when describing outages in electrical transmission facilities, with attention to both outage occurrences and outage states. In practice, that means it supports a common framework for identifying what happened, when it happened, and how the affected facility should be characterized during reporting or analysis. IEEE P859/D2, Nov 2017 is useful where transmission equipment performance, availability, and event records must be interpreted consistently across teams or organizations.

Typical use cases

IEEE P859/D2, Nov 2017 may be used when utilities, transmission operators, consultants, or asset-management teams prepare outage reports, review event logs, or compare facility performance over time. It is especially relevant for transmission lines, substations, and related power-system equipment where outage status needs to be recorded in a uniform way. The standard can also help support internal analysis workflows, reliability studies, and data exchange between engineering and operations groups using the same terminology.

Why it matters

Consistent outage terminology is important because it reduces ambiguity in reporting, supports cleaner data analysis, and improves confidence in operational records. IEEE P859/D2, Nov 2017 can help organizations apply the same definitions when assessing transmission-facility availability, reviewing incident history, or preparing compliance-related documentation. For teams working on planning, maintenance, or reliability, that consistency may reduce interpretation errors and make comparisons across assets or reporting periods more dependable.

• Outage occurrence terminology
• Outage state definitions
• Transmission facility reporting
• Event analysis and recordkeeping
• Consistency across engineering teams