The two key industry measures of network performance are:
- the average number of outages per customer per year (SAIFI: system average interruption frequency index);
- and the average total duration of outages per customer per year (SAIDI: system average interruption duration index).
In the 2018 financial year we met the SAIFI and SAIDI targets set by the Commerce Commission. On average an Orion customer would have had 1.0 network outages for a total of about 79 minutes without power.
'Table of rules'
Our 2018 SAIDI and SAIFI targets are included in our Security of Supply standard, the 'table of rules' that describes the service we aim to provide on our network. It defines whether the power will go out if something fails on our network, and the length of time that customers can then expect to be without power.