P359 ‘Mechanised process for GC/DC declarations’

Formal title: Mechanised process for GC/DC declarations

Current Status

Initial Written Assessment
Assessment Procedure
Report Phase
With Authority
Awaiting Implementation


P359 seeks to introduce a new mechanised process for Generation Capacity (GC) and Demand Capacity (DC) re-declarations following a ‘GC/DC breach’.


P359 was successfully implemented on 28 February 2019 as part of the February 2019 BSC Release.

The Assessment Report was presented to the BSC Panel on 10 May 2018. The Panel unanimously recommended that P359 should be approved. The Report Phase Consultation was issued on 15 May. Responses are invited by 1 June 2018.

At its meeting on 14 September 2017, the Panel agreed Elexon’s recommendation to send this Modification to the Assessment Procedure.

As Elexon was not able to attract the minimum number of five members to join the P359 Workgroup, the response deadline for joining the Workgroup was extended for two weeks, which resulted in a one month delay.

The first Workgroup meeting was held on 19 October 2017. As part of the solution development, the Workgroup requested that Elexon conduct further analysis on eight different areas. The Workgroup agreed that the next meeting should be held following the completion of the analysis, to ensure that the work could be considered in its totality. Elexon discussed the impact this would have on the timeline with the Workgroup. Based on the required analysis,and competing commitments from other Industry Workgroups, the Workgroup agreed that it would be sensible to hold the next meeting in the New Year, which would result in a three month delay.

Due to the delay in forming the first Workgroup, and the length of time required to complete the analysis, the BSC Panel agreed a four month extension to the Assessment Procedure Consultation at the November 2017 meeting.

The second P359 Workgroup was held on 23 January 2018. Following the meeting, Elexon circulated draft business requirements to the Workgroup and service providers for impact assessment. Elexon’s service providers provided a response and costings to both sets of Business Requirements. In their response Elexon’s service providers highlighted a number of enhancements to the automated solution for Elexon to consider. As such, the business requirements for the automated solution were re-issued for a second impact assessment, to ensure that the solution is costed correctly ahead of the next Workgroup meeting. This resulted in the pre-arranged meeting being postponed by a fortnight. For this reason, a one month extension was approved by the March 2018 BSC Panel.

The third P359 Workgroup was held 6 March 2018. The Assessment Procedure Consultation was issued on 20 March 2018, with responses due by 6 April 2018. The majority of respondents agreed with the Workgroup that P359 should be approved.

The fourth P359 meeting took place on 20 April 2018, where the Workgroup considered the responses to the Assessment Procedure Consultation. The majority of the Workgroup believes that the P359 would better facilitate Applicable BSC Objectives (c) and (d) compared to the current baseline and so should be approved.

The Assessment Report was presented to the BSC Panel on 10 May 2018. The Panel unanimously recommended that P359 should be approved.

The Draft Modification Report is due to be presented to the BSC Panel on 14 June 2018. The BSC Panel recommended that P359 should be approved. The Final Modification Report was issued to the Authority for decision on 15 June 2018.

The Authority approved P359 on 17 August 2018 for implementation on 28 February 2019, as part of the February 2019 BSC Release.

Next Events

No further events related to P359 planned.


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