SAIDI & SAIFI

Reliability Indices


System Average Interruption Frequency Index (SAIFI)

The System Average Interruption Frequency Index (SAIFI) is the average number of interruptions that a customer experiences and is calculated as:
SAIFI = total number of customer interruptions ÷ total number of customers served 
SAIFI is measured in units of interruptions per customer. It is usually measured over the course of a year in accordance to IEEE Standard 1366-2003.

System Average Interruption Duration Index (SAIDI)

The System Average Interruption Duration Index (SAIDI) is the average outage duration for each customer served and is calculated as:
SAIDI = sum of all customer interruptions ÷ total number of customers served
SAIDI is measured in units of time, often minutes or hours. It is usually measured over the course of a year in accordance to IEEE Standard 1366-2003

 

SAIDI & SAIFI VALUES FOR NAIROBI

Nairobi County Reliability Indices for the period January  to December 2018

Region

No. of incidences

Sum of numerator for SAIFI

Sum of Numerator for SAIDI

No. of Customers

SAIDI

SAIFI

CAIDI

Nairobi North

19,214

3,957,062.83

8,115,489.63

797,669

10.17

4.96

2.05

Nairobi South

15,225

6,779,414.667

10,595,050.02

764,774

13.85

8.86

1.56

Nairobi West

8,288

4,107,644.33

7,076,130.10

585,987

12.08

7.01

1.72

Grand Total

42,727

14,844,121.83

25,786,669.75

2,148,430

12.00

6.91

1.74