Nexus WorkgroupRead Validation Scenarios

4th December 2013

Background

• Read Validation rules and tolerances developed during the Settlement BRD

• Concern raised at 30th October workgroup that the tolerances may not be appropriate for Class 4 sites as a ‘flat profile’ is used (AQ / 365 x no. of days in period).

• Workgroup agreed the principle of read validation was correct but would like to examine the tolerances further

• The following slides provide a list of various scenarios considered by Xoserve during analysis of the AQ requirements to validate the principles & tolerances described in the BRD

Scenarios

1. AQ = 1 – Reason: the site has not been consuming gas for over 9 months– Consequence: read will fail validation – Outcome: AQ Correction process used to re-calculate the AQ

then re-submit the read

2. AQ is significantly higher or lower than sites predicted consumption– Reason: change in plant or site previously ‘mothballed’– Consequence: read may fail validation– Outcome: AQ Correction process used to re-calculate the AQ

then re-submit the read

Scenarios cont.

3. Site Isolated– AQ would carry over until 9 months consumption was available

during the non-isolated period therefore read would not fail

4. Vacant site– AQ would reduce as reads are loaded with zero/low consumption

over a period– If read fails due to the AQ being low, the AQ Correction process to

be used to amend AQ

5. Round The Clock value incorrect/not populated– Read would fail due to out of tolerance– Re-submit read with correct ‘Round the Clock’ (TTZ) count

Scenarios cont.

6. Change of Class – Class 4 to 2– SOQ is used to validate the reads, Shipper nominates the SOQ

7. Change of Class – Class 2 to 4– Daily reads previously loaded for site and AQ reviewed monthly.

Reads should therefore pass the validations based on AQ