Image of back arrow Back to filtered results

XRN 5535A
Processing of CSS Switch Requests Received in ‘Time Period 5’

Last Updated
28 Mar 2023
Release Type
Implementation Date
06 Mar 2023
Proposer Xoserve Impacted DSC service area

Service Area 3 (Current Apr 21)

Manage updates to customer portfolio

Customer Change Team Leader


The circumstances where the GRDA receives messages after 02:59:59 should be exceptionally rare – i.e. systems have failed in normal operation; the resilience built into the system to maintain contiguous service have failed such that they cannot be restored within the 1 hour RTO; Target DR Recovery has been missed AND Maximum DR Recovery has also been missed.

Since this change is required in such rare circumstances this change needs to identify a solution that is cost effective to implement so that these Registrations can be recorded in UK Link systems.

The analysis needs to engage stakeholders to determine the risk / impact of the solution to all industry participants.

This change should focus on short term options for implementation.  It is not proposed to initiate a large investment given the extremely low likelihood of this scenario occurring.

Impacted Customer Types

  • IGT
  • NGT
  • Shipper
  • DNO


Document title Comment Last updated CHMC outcome
Change Proposal Approved 30/01/2023 Approved at ChMC on 13/07/2022
Initial Review Stage not required N/A N/A
DSG Discussion N/A 01/03/2023 N/A
High Level Solution Options Stage not required N/A N/A
Solution Review Stage not required N/A N/A
Detailed Design 3139.5 - VO - PO 13/03/2023 Approved at ChMC 08/03/2023
Evaluation Quotation Reports (EQR) Stage not required N/A N/A
Business Evaluation Reports (BER) Approved 13/02/2023 Approved at ChMC 08/02/2023
Change Completion Reports (CCR) Stage not yet reached N/A N/A


Initial Review
Change Proposal Raised 01/07/22
Status Awaiting approval at ChMC
Approved into Capture 13/07/22
Status ChMC approved into Capture
Solution Consultation
Expected: 00/00/00
Status Stage not required
Awaiting Delivery
Expected: 00/00/00
Status Stage not required
In Delivery
BER approved 08/02/23
Status Detailed Design Change Pack approved at ChMC 08/03/2023
Expected: 06/03/23
Status Successfully Implemented

Contact the Change Team

Need to get in touch with a member of the Change Team?

You can email us at: and we'll get back on the same day between the hours of 9:00am to 4:30pm.