1. Development Work Group 194
Overview of RbD Verification
27 March 2008

2. RbD Verification – Background
Purpose
RbD Verification was one the assurance activities to support the introduction of RbD in 1998
Designed to give a view as to whether RbD gives the same results as Meter Point Reconciliation within a statistical tolerance
How
Verification uses the “Domestic Monitor Panel” of customers maintained by British Gas
Customers read their meter every week, submit reads monthly
Verification calculates actual consumption from those reads
Compares actual energy consumed against amounts billed via Commodity and RbD for those customers
Scales up the results to match each LDZ mix of sites and calculates a total difference in kWh per LDZ

3. RbD Verification Outputs
Comparison of actual v. billed by customer by month
Commodity
RbD
LDZ
LDZ
LDZ
DMP
LDZ
KWh Actual total
KWh Billed total
Explanatory
items
Remaining imbalance table

4. Verification – Explanatory Items
Initial imbalance is adjusted for items which are:
not present in the sample
not yet processed via invoices
Phasing by month unknown – totals only available

5. Current adjusting items
Domestic Monitor Panel scaled up, plus …
Unavoidable items not in sample
Unidentified Theft of Gas (downstream)
Late confirmed sites (orphaned energy)
Historic known issues which cannot be corrected, not present in the sample, e.g.
Threshold crosser exclusions (Mod 640)
LDZ/postcode discrepancies
Inter-LDZ unmetered transfers
Total billing via Commodity/RbD, less …
Timing issues, e.g.
Unprocessed LDZ Reconciliations
Unprocessed financial adjustments (duplicates)
Threshold crosser adjustments not yet processed
Annual Shrinkage adjustment not yet processed
Initial graph
Difference after adjusting items is the remaining imbalance

6. Latest RbD Verification slides – December 2007
Data available up to September 2007
National figures only reproduced (LDZ level shared with RbD Sub-Group)
Statistical confidence levels:
+/- 1.3% nationally
Typically +/- 2.5% per LDZ
Next update due at RbD Sub-Group, 8 April 2008

7. National Verification Update – 4 year History

8. RbD Imbalance – 4 year History
Note: Items removed as a result of move to 4 year analysis include Temperature and Pressure Adjustments, Threshold Crossers 2000 to 2003 and Historical Shrinkage Adjustment

9. RbD Imbalance continued – 4 year History

10. Imbalance Breakdown – 4 year History.