This part of IEC 61400 , which is a Technical Specification, specifies terms and information categories for identification and reporting of reliability metrics. The definitions are applicable to key components, any number of wind turbines, fleets of wind turbine types, a wind power station or a portfolio of wind power stations. The wind power station is made up of all WTGSs (Wind Turbine Generator Systems), functional services and balance of plant elements as seen from the point of common coupling.

This document provides guidelines regarding reliability methodologies with informative annexes regarding use.

It expands on the information model in IEC 61400‑26‑1, recognizing that availability and reliability are interrelated.

It does not assign specific reliability specifications, constraints or targets but rather provides standardized means of categorizing and prioritizing data and illustrates the use of the model and metrics in informative annexes.

It does not specify the method of information acquisition or specific use. Beyond that, it is not the intention of this document to specify exactly how to calculate other undefined or performance-based reliability metrics.