1. Systems Impact from Gas Day Change
Meeting Monday 5th August 2013
Hayley Burden

2. NTS System Impact Assessment – Stage 1
An initial high-level review of the impact of gas day change on our core business system (iGMS) has been carried out.
Initial findings indicated that:
The change is significant and widespread.
Core calculations and processing will be affected.
Numerous upstream and downstream dependencies exist.
Extensive analysis and testing will be required to understand the full implications. 2

3. NTS System Impact Assessment – Stage 2
As a result of these findings, a more detailed phase of analysis has been initiated to:-
Consider the wider scope of all Transmission systems.
Capture more details of the impacts from a systems perspective on scheduled processes, data, calculations and interfaces.
Report on the scale and complexity of the impact.
Quantify options to reduce the impact of the change.
Rough Order of Magnitude (ROM) costs and indicative timescales of a delivery programme. 3

4. Stage 2 - Timescales
The analysis being completed by NG IS and Xoserve is due to be delivered by the end of October 2013.
NG NTS intend to share the outcome of this with the Mod 461 WG members
( NB. Analysis is also being completed by Xoserve for Distribution. This is a separate piece of work but being completed in parallel for efficiency purposes)