On this page you will find information to guide your planning activities for the MHHS Programme.

At the Programme Steering Group (PSG) on 8 June 2023, Change Request 022 (CR022) was approved following Ofgem’s approval of Level 1 milestone changes. PSG agreed that version 5.0 of the MHHS Programme Plan would be adopted as the baseline change.

The below Plan on a Page (PoaP) is the Baselined MHHS Implementation Timeline that articulates the delivery stages of the Programme.  ​​​​Click on the image below to open an enlarged version.

Baselined MHHS Implementation Timeline

Delivery of the MHHS Programme is phased: there are three defining critical paths to starting migration:

  1. Systems Integration Testing (SIT) Minimum Viable Cohort (MVC), who participate in SIT and qualify via the Qualification Assessment Document (QAD) process to reach the earliest migration start Critical Path 1 (CP1). Other SIT Programme participants can Go-Live between Critical Path 2 (CP2) and Critical Path 3 (CP3).
  2. Participants who do not participate in SIT but reach early migration via Tranche 1 of Qualification (CP3).
  3. Other participants will pursue the Qualification route (in later tranches).

You can find more information on the Baselined Plan, Milestone Register and Implementation Approach on the Programme Plan & Complementary Documents page of this website.

Key information to support your navigation of the Programme

Which deliverables are out for review and what are key dates that I need to be aware of?

The Participant Checklist (previously the Master Consultation Dashboard) is a checklist to keep Programme participants up to date with Programme requests for review and engagement.

You can view the checklist below:

Participant Checklist


What are the Programme governance meetings that I need to attend and where can I find information on them?

Visit the Events page of this website


Where can I find information on the Critical Path my organisation is on regarding Testing and Qualification responsibilities?

  • If you are non-SIT participant: view the document below:

Non-Sit Supplier Journey through the MHHS Programme