Dr. Roy Billinton, father of SAIDI and SAIFI, 1935-2025

Dr. Roy Billinton, one of the pioneers of reliability intelligence in the electricity industry passed away last December at the age of 90.

Born in the UK, Dr. Billinton was on faculty at the University of Saskatchewan since 1969, where he held many roles within the College of Engineering for four decades. Professor, Head of Electrical Engineering, Assistant Dean, Associate Dean, Dean, and Distinguished Emeritus Professor of the College of Engineering.

According to his obituary by the Institute of Electrical and Electronics Engineers (IEEE) North Saskatchewan chapter, Dr. Billinton was “widely regarded as a founder of the modern discipline of power system reliability engineering, Dr. Billinton authored or co-authored 10 books and more than 975 technical papers and mentored over 135 graduate students. His work bridged theory and practice—supporting utilities and practitioners worldwide through extensive consulting, presentations, and more than 100 short courses delivered internationally.”

One of Dr. Billinton’s greatest contributions to reliability electricity industry was his development of SAIDI (System Average Interruption Duration Index), measures the average total duration of power outages, and SAIFI (System Average Interruption Frequency Index), which measures the average number of times a customer experiences an outage. Since they were introduced in the early 1970s, SAIDI and SAIFI are used internationally as some of the key metrics used by electrical utilities to measure grid reliability.

Electricity Canada offers its condolences to Dr. Billinton’s family and colleagues.