Programme Overview

MHHS Programme Objective

To maximise the opportunities provided by smart metering by developing and implementing an enduring process for MHHS, that delivers benefits for consumers and enables a smart, flexible energy system.

In June 2023, Ofgem approved a revised date for the introduction of the new MHHS Settlement code at Milestone 16 (M16) to December 2026, following the Programme Steering Group's (PSG) recommendation to approve CR022: MHHS Programme Replan after extensive industry consultation.  

For more information on the Programme plan, implementation and delivery, please visit the Programme Plan & Complementary Documents page of this website.


MHHS Programme Roles

Ofgem, acting as Programme Sponsor, has placed the responsibility for the management and delivery of the MHHS Programme with the industry. Ofgem appointed Elexon to act as the Senior Responsible Owner (SRO) and MHHS Implementation Manager (IM).

The Programme is supported by an industry selected Programme Steering Group (PSG) which is the Programme’s primary decision-making body and chaired by the SRO.

Ofgem have appointed PricewaterhouseCoopers (PwC) to the role of Market-wide Half-Hourly Settlement (MHHS) Independent Programme Assurance (IPA) provider. The IPA are mobilised and working with the Programme.

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Lead Delivery Partner

Following a thorough procurement process Expleo Technology UK Limited (with their subsidiary company, Moorhouse Consulting Limited) were appointed as the Lead Delivery Partner (LDP) for the Market-wide Half-Hourly Settlement (MHHS) Programme.

Expleo provide Central Programme Team, Programme Management Office, Programme Party Coordinator, and System Integrator functions.

Expleo colleagues joined the MHHS Programme in December 2021. Resource levels and skills are changing as required to meet the needs of the Programme.


Elexon Business Separation Plan

Ofgem has approved revisions to Elexon's Business Separation Plan for the MHHS Programme. The updated version can be found below, along with a red-lined version vs the original.

Elexon's Business Separation Plan v2.0

Elexon's Business Separation Plan red-lined version

Ofgem commented: "We consider that, as amended, it continues to provide a reasonable basis for ensuring that the service providers, personnel, IT Systems and facilities that Elexon uses to perform its role as MHHS Implementation Manager are sufficiently separated from those it uses as an MHHS participant."

The Business Separation Plan continues to support the required physical, organisational and cultural programme separation.

Elexon has implemented internal controls to monitor compliance with the Business Separation Plan and the ongoing management of the potential conflict of interest risk. The Independent Programme Assurance (IPA) provider will monitor and provide assurance that Elexon complies with its obligations and is responsible for identifying and reporting on issues relating to business separation and Elexon’s conflict of interest.

If you are concerned about a conflict of interest and you would like to discuss it with the Programme team, please email us at [email protected] 


High-level Programme Structure


The Lead Delivery Partner (LDP) is required to deliver four key service roles:

  1. Central Programme Team (CPT)
  2. Programme Management Office (PMO)
  3. Programme Party Coordinator (PPC)
  4. Systems Integrator (SI)

An industry-led governance model ensures the decision-making between the SRO, Implementation Manager (IM) and MHHS Programme participants is appropriately balanced. This model ensures that the SRO is empowered to make decisions on behalf of the industry, but is accountable to, and has engaged and consulted with MHHS Programme participants.


Target Operating Model

One of the key outputs of Ofgem’s initial electricity settlement reform Significant Code Review (SCR) was the development of a Target Operating Model (TOM) to deliver market-wide half-hourly settlement.

A series of Working Groups contributed to developing the TOM that Ofgem published in October 2019. These groups were a Design Working Group, a Code Change and Development Group, an Architecture Working Group and a Design Advisory Board.

MHHS Design will support the Target Operating Model across the industry.