Frequency of Reporting:  Quarterly​

Transmission Availability Data System
Transmission Availability Data System efforts began in 2006 under guidance of the NERC Planning Committee. TADS is a web based system used to report and collect system inventory and transmission outage data, in a common format.

A decision tree is available in the NERC TADS Data Reporting Instructions (page vi), which defines what element outages need to be reported in TADS.

NERC uses the information available in TADS to develop transmission system metrics, analyzing outage frequency, duration, causes, and other factors related to transmission outages. NERC also provides a public report with TADS data aggregated for each Region.

Provision of TADS data is mandatory for all U.S. TOs on the NERC Compliance Registry. Per Section 1600, non-U.S. Transmission Owners on the NERC Compliance Registry are required to provide Non-Automatic outage TADS data. For additional information, refer to the Data Reporting Instructions on the NERC TADS website.

MRO's Role
MRO staff primarily function as TADS administrators. MRO assists NERC staff in initial registration of users and organizations, as well as overseeing data entry prior to aggregation at the NERC level. At the end of each reporting period, MRO staff ensure that all TADS data forms have been completed by each Functional Entity. Additionally, MRO performs data validation to ensure any flagged content is revised by the end of the regional reporting period. Upon conclusion of the Regional Entity data review, NERC staff will begin their aggregation and review of the reporting period's data.

Data is collected via the NERC OATI webTADS application. The TADS reporting manual is updated annually and is available on the NERC TADS website.

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