SoP 011 - A : System Average Interrruption Frequency Index (SAIFI) for Urban category
4th  Quarter Year - 2008-09
Sr.
No
Month Ni - Number of Customers for each sustained interruptions (in numbers) NT - Total No of customers served
(in Numbers)
SAIFI = Ni/Nt
(Monthly SAIFI)
1 2 3 4 5= 3 / 4
1 Apr-08 4496734.3 1651801.5 2.72
2 May-08 2283696 1642324 1.39
3 Jun-08 2283696 1642324 1.39
SoP 011 - B : System Average Interrruption Duration Index (SAIDI) for Urban category
4th  Quarter Year - 2008-09
Sr.
No
Month Ri =
Restoration Time for each sustained interruption event
(in hours)
Ni - Number of interrupted Customers for each sustained interruption event
(in numbers)
Ri* Ni -
Total customer interrution Duration
NT - Total No of customers served
(in Numbers)
SAIDI = Ri*Ni/Nt
(Monthly SAIDI)
1 2 3 4 5 = 3 * 4 6 7= 5 / 6
1 Apr-08 785.41 5170 4060639.41 1651802 2.46
2 May-08 565.58 3993 2258396.98 1642324 1.38
3 Jun-08 565.58 3993 2258396.98 1642324 1.38
SoP 011 - C : Momentary Average Interruption Frequency Index (MAIFI) for Urban category
4th  Quarter Year - 2008-09
Sr.
No
Month IMi =
Number of Momentary interruptions for the month
(in numbers)
Nmi =
Total no of customers for each momentary interruptions
(in numbers)
Imi =Nmi
Number of customer Mementary interruptions
(in numbers)
Nt -
Total no of customers served
(in numbers)
MAIFI=
Imi*Nmi/
Nt
1 2 3 4 5 = 3 * 4 6 7= 5 / 6
1 Apr-08 3419 8085 27641389 1651802 16.73
2 May-08 2198 4199 9228772 1642324 5.62
3 Jun-08 2198 4199 9228772 1642324 5.62