CSS Design and Delivery Products

Publication date
22nd June 2018
Information types
Policy areas

This suite of documents represents the detailed design for the Central Switching Service (CSS) that will be required to deliver the new End to End Switching Design and Delivery Arrangements. They provide the specifications that will be used to support the forthcoming procurement of the CSS that should also be used to assist the update of existing actors’ systems and processes.

These products should be read in conjunction with the Switching Programme: Outline Business Case and Blueprint phase decision, which was published on 12 February 2018.

These products will form the basis for the Enactment Phase of the Switching Programme and will be subject to formal change control going forward. Therefore these products represent version 1 of the CSS Design.

The products will be of particular interest to those industry actors who are actively involved in the current switching processes or are considering entering the market.

The table below summarises latest product versions and publication dates. To see details of the Change Requests referenced in the table below, please see the Switching Programme change control log on our Change Management page.

Product name and PBS reference  Version number Date of publication and comments
D-4.2.1 CSS User Requirements Specification V2.1 This product was published on 17 December 2018 and incorporates amendments agreed in Change Requests CR-E08, CR-E10, CR-E12, CR-E17, and CR-E18.
D-4.2.2 CSS Detailed Non-Functional Requirements V2.1 This product was published on 17 December 2018 and incorporates amendments agreed in Change Requests CR-E03, CR-E11, and CR-E13.  
D-4.2.4 CSS Delivery Plans V2.0 This product was published on 22 June 2018
D-4.2.6 CSS Data Migration Plan V2.0 This product was published on 22 June 2018
D-4.2.8 CSS Communications Network Requirements V1.0 This product was published on 22 June 2018.

Please note: D-4.2.3 CSS Service Management and Operational Approach can be found on the CSS Service Management page 

To view the programme change process and information on change requests impacting baselined products, please visit the Switching Programme Change Management page.

To access red-lined versions of the above products, please contact SwitchingPMO@ofgem.gov.uk