The SGS Study offers statistical rigor and distinct benefits compared to other benchmarking venues. The
SGS Study is offered to the US-Canada electric transmission industry each year since 1995. Important
features of the SGS Study include:
- Actionable, Individualized Circuit-Level Measures for each and every circuit to help prioritize reliability improvement and
investment decisions by asset managers and engineers.
- Delivery Point benchmarking measures for the impact of transmission line outages on distribution, using IEEE Std 1366
statistics for system, voltage class and individual circuit level.
- Major Event Day screening using statistical methods which insure precise, “apples versus apples” comparisons based
on raw circuit outage data.
- Ease of Participation and Use: Simply provide a download of 5 or more years of outage data and an inventory of
transmission lines. No complicated questionnaires or surveys, No time consuming planning meetings, No lengthy
conference calls, No D-I-Y queries or extracts to get your information.
- Long-Term Trend Charting: All good quality outage data is utilized to provide long-term trend charts (most systems
provide 10+ years of data). Such long term trend charting is unavailable in other benchmarking forums.
- Measures: 30 different SGS performance measures, 12 TADS metrics, analysis of 10 outage cause categories plus
innovative composite scoring (TACS), by system, opco, voltage class and circuit.
- he Most Complete and in-depth transmission reliability benchmarking available for Subtransmission through EHV
voltages, reported by system and operating company-levels, industry averages, top decile, quartiles by voltage class
- Results are presented at a user conference in May; conference time is also devoted to participant presentations on
reliability management and analysis.
- Systems receive a hard-copy Summary report and additional PDF documents consisting of an Extended Summary,
detailed Report (including outage cause comparisons and trends), a NERC TADS Supplement of most TADS measures
and Delivery Point results (if submitted) and multiple output data files. There are approximately 1800 document pages
and 20 MB of output files – it provides multiple levels of granularity for system, voltage and circuit performance
benchmarks for dozens of measures.
The SGS Study has set the standard for benchmarking transmission reliability since 1995. The SGS Study utilizes
5+ years of raw transmission circuit outage data and applies common rules to all systems to insure the highest
integrity of analysis and comparisons.
Detailed Features of the SGS Study:
DELIVERABLES: A 300+ page Study, customized company-specific Summary (30+ pages), Extended Summary and NERC
TADS Supplement, electronic data files and a 1 day participant conference (deliverables, CD). More than 30 different
reliability performance measures are provided at a circuit-, voltage class- and system-level.
EASE OF PARTICIPATION: Simply provide a down-load of raw transmission outage data and circuit inventory (see data
submission example). There are no complicated surveys or spreadsheets to complete. A low commitment of internal time and
resources for participants.
VALIDITY OF COMPARISONS: The Study pools raw outage data and uses common methods process each participants and
to screen major event days (pooling data).
TIMELY RESULTS CONFERENCE: Results are presented at a participant Conference in May 2019. Includes participant
presentations about internal reliability management practices.
COMPREHENSIVE: Comparisons by voltage class against the industry average and individual systems (bar chart, trend
GRANULARITY: Precise circuit-level performance measures for reliability management decision support. Annual and multi-
year averages of circuit level performance.
CUSTOMER and DELIVERY POINT ANALYSIS: IEEE Std 1366 and other reliability measures and benchmarking are
provided for transmission line outages affecting Customers or Delivery Points by system, voltage class and individual circuits
OUTAGE CAUSE ANALYSIS: Participant classify their internal outage cause descriptions into nine Study categories.
Analysis is provided at the voltage class (bar charts, trend charts and tables) and circuit level output.
CABLE: Comparison of cable reliability performance (voltage class, individual circuits).
NERC TADS PERFORMANCE METRICS: The Study has a complete section utilizing 12 of the 16 NERC TADS metrics
(Transmission Availability Data System) for AC transmission lines. The SGS Study provides your system an advance view of
its performance under NERC TADS with benchmarks to the industry and your peers, which are not provided in any NERC
reports View sample NERC TADS report.
COMPLETE PERFORMANCE METRICS: The Study uses performance metrics defined by NERC, IEEE and CIGRE working
groups, plus innovative reliability statistics (time between failures).
COST: Participation cost is determined by system size for transmission owners and is competitive with other independent
To view examples of typical SGS Study output and deliverables and a discussion of Study applications, click on the following
link to view PDF of slides:
There is a formal project proposal and data requirements documents which are sent upon request in January.
The STUDY TIMELINE: data submission/reconciliation process (Q1), analysis phase (Q1-April), preliminary Report (April)
conference (May) and on-going free user support (Q3-Q4).
Over the years, the SGS Study represented over 60% of the US-Canada transmission grid
SGS Study Participant List, 2000-2019
participant. Listing does not constitute an advertisement or endorsement of the study. Participants are listed to provide an
example of the type of systems likely in future years.
Corporate Name (Parent or Final Merged Entity)
- American Electric Power (AEP)
- Central & Southwest (AEP)
- Arizona Public Service (APS)
- American Transmission Company (ATC)
- Wisconsin Electric Power (ATC)
- BC Hydro (BCHYRDO)
- BC Transmission Corp. (BCHYRDO)
- Bonneville Power Administration (BPA)
- CLECO Energy (CLECO)
- Dominion Resources (DOM)
- Duquesne Light (DQE)
- Duke Energy (DUKE)
- Progress Energy (DUKE)
- Carolina Power & Light (DUKE)
- Entergy Services (ENTERGY)
- Exelon Corp. (EXELON)
- Commonwealth Edison (EXELON)
- PECO Energy (EXELON)
- Batlimore Gas & Electric (EXELON)
- First Energy (FE)
- General Public Ulilities (FE)
- Allegheny Power (FE)
- Florida Power & Light (FPL)
- Great River Energy (GRE)
- Georgia Transmission Corp. (GTC)
- Hydro One Networks (HYDRO ONE)
- Idaho Power Company (IDAHO)
- ITC Holdings (ITC)
- Michigan Electric Transmission Company (ITC)
- Consumers Energy (ITC)
- Lower Colorado River Authority (LCRA)
- Long Island Power Authority (LIPA)
- Keyspan Energy (LIPA)
- Municipal Electric Authority of Georgia (MEAG)
- National Grid (NGRID)
- Niagara Mohawk (NGRID)
- Nebraska Public Power District (NPPD)
- Northeast Ulitities (NU)
- Montana Power Company (NWE)
- Northwestern Energy (NWE)
- New York Power Authority (NYPA)
- New York State Electric & Gas (NYSEG)
- Oncor Electric Delivery (ONCOR)
- TXU (ONCOR)
- Pacificorp (PACIFICORP)
- Pacific Gas & Electric (PGE)
- Public Service of New Mexico (PNM)
- Public Service Electric & Gas (PSEG)
- South Carolina Electric & Gas (SCEG)
- San Diego Gas & Electric (SDGE)
- Seminole Electric Power Cooperative (SEMINOLE)
- Southern Company (SOUTHERN)
- Georgia Power Company (SOUTHERN)
- Salt Rover Project (SRP)
- Tucson Electric Power (TEP)
- Tennesee Valley Authority (TVA)
- Xcel Energy (XCEL)
- Northern States Power (XCEL)
* 3.2 SGS will identify Company as a Study Participant in the body of the Report, Summaries and in marketing the Study and services to prospective clients. Identification of Company as a Study Participant will not
be used as an endorsement of the Study by Company without prior approval of Company's representative.
SGS Transmission Reliability Benchmarking Study
Imitated, never replicated!