Key Safety Indicator

Aspect Measured

Safety

Network and public safety

Measurement

Accuracy and reliability of gas metering and
measurement of gas heating value.

Quality

Natural gas quality

Reliability

Reliability of gas supply and equipment.

Item

Description

Allowable

Actual

Safety -11.

Number of over pressurization
incidents in networks per month

2.

Number of complaints of
detectability of gas by odour.

3.

Number of gas outages

4.

Regulator failures and number of
instances of above agreed
maximum allowable operating
pressure.

5.

Number ,of times damage
occurred to the main transmission system

6.

Number of leaks from the
transmission system.

7.

Number of fires caused by a gas
leak in the transmission system.

8.

Number of meter retest requests.

9.

Number of retest requests with
response time exceeding 3 days.

Number of defective metres

11

12. Gas Quality

13.

14.

15.

16.

17.

18

Reliability

19.

20.

21

22.

23

Percentage of meters tested within
the accuracy limits of the meters
class.

Quality of gas entering transmission
system

Quality of gas exiting transmission
system

Number of instances of off-spec gas

Total duration of occurrence of off-
spec gas off taken from system

Number of instances of non-
compliant gas

Total duration of occurrence of non-
compliant gas entry into system

Total unaccounted for gas

Number of leaks reported.

Number of complaints of low
supply pressure

Aggregate of planned gas outages

Aggregate of unplanned gas outages
Aggregate of number of hours lost
through unplanned outages