Reliability Metrics

• What do the reliability indices mean? • And, how do I leverage them to increase my

reliability?

Tony Thomas – NRECA Business and Technology Solutions

Reliability Indices:

• SAIDI: System Average Interruption Duration Index – This is the total duration of interruption for the average customer per

year – Measured in minutes

• CAIDI: Customer Average Interruption Index – This the average time required to restore service. – Measured in minutes

• SAIFI: System Average Frequency Duration Index – Number of outages for the average customer per year – Measured in Each.

1 TechAdvantage 2015

SAIDI = CAIDI X SAIFI

IEEE 1366

• Major Event Days (MED) • SAIDI is modified by MED to better reveal

trends in daily operation that would be hidden by the large statistical effect of major events.

• It’s not the yearly snapshot that’s important. It’s the trend over time that’s important.

1 TechAdvantage 2015

SAIDI trending up over time

This is an example of a SAIDI score that is trending up over time. Note the removal of MED’s reveals the trend that would be hidden in the data.

TechAdvantage 2015 4

Typical SAIDI Trend

TechAdvantage 2015 5

TechAdvantage 2015 6

TechAdvantage 2015 7

TechAdvantage 2015 8

TechAdvantage 2015 9

TechAdvantage 2015 10

TechAdvantage 2015 11

TechAdvantage 2015 12

Evaluate

Goal Setting

Plan Execute

Measure

Process Management Cycle

PwrMetrix is a tool that enables you to turn reliability into a process management opportunity.

Thank you

Tony Thomas tony.thomas@nreca.coop

703.907.5824