Systems Integration Testing (SIT)

What is SIT?

Systems Integration Testing (SIT) will test the end-to-end (E2E) MHHS Design, ensuring that the new MHHS arrangements function correctly and have been implemented in accordance with the MHHS E2E description.

Participants will demonstrate functional, non-functional and migration-related characteristics of the Market Interfaces and Services in an integrated, end-to-end environment.

For most participants, SIT is a voluntary phase of the Programme. SIT will not start until all Core Capability Providers have completed their design, build and Pre-Integration Testing (PIT). The number and types of participants joining SIT must be sufficient to form the Minimal Viable Cohort (MVC). You can view the timeline for SIT in the PoaP in the Quick Links.

In February 2023, we held a webinar to support participants in their understanding of SIT. You can view the slides, recording and Q&A on the MHHS Open Days and Webinars page of this website.

The Component Integration Testing (CIT) phase of SIT will begin from 30 October 2023. SIT Volunteers will be progressively onboarded according to their system and role. 

SIT Plan on a Page

For more information on SIT and the benefits of joining SIT, please read the SIT Overview document:

SIT Overview document

If you have any questions on SIT, please email [email protected]



Paths to Migration

To verify participants’ fitness to take part in the new Half-Hourly arrangements, participants must test their systems for compliance with the E2E MHHS Design.

There are two paths to migration, either via Qualification Testing, or the earlier route of SIT.

If participants take part in SIT, they are not currently expected to undergo additional Qualification Testing in the Qualification phase.

SIT Pre-requisites  

  • Programme responsibility: The SIT scenarios specified by the Systems Integrator (SI) team, demonstrating functional, non-functional and migration-related characteristics of the Market Interfaces and Services in an integrated environment. 
  • Participant responsibility: Evidenced Pre-Integration Testing (PIT) executed in your own environment.

Defect Management Plan

The Programme has baselined the Defect Management Plan which is available below:

Defect Management Plan

The document describes the overall approach to managing defects within the industry testing phases of the MHHS Programme. The purpose of the plan is to support the timely and efficient raising, triage, categorisation, and resolution of defects. 

It also describes the defect assignment and process workflow, along with state definitions and transition states. 



Systems Integration Testing (SIT) Functional Participant Readiness Report Template

The Systems Integration Testing (SIT) Functional Participant Readiness Report Template is now available. 

The Systems Integration Testing (SIT) Functional Participant Readiness Report is used by SIT participants to demonstrate and self-declare the preparedness of testing efforts for their organisation as they enter SIT Functional. As a key milestone before testing activities start, this report aims to ensure that all necessary components and prerequisites are in place to conduct testing efficiently and effectively.  

The deadline for submitting your completed SIT Functional Participant Readiness Report passed on Wednesday 14 February.

We ask that participants with outstanding SIT Functional Readiness Reports please provide these to the Programme as soon as possible. The completed report is a formal self-declaration of the participants SIT Functional readiness status in relation to the preparation activities as outlined in the SIT Functional Test Approach and Plan

Use of the agreed template for documenting the SIT Functional Readiness Report is mandatory for all SIT participants. Participants may add additional sections as they feel appropriate but cannot remove any sections or information contained in the template. 

SIT Functional Participant Readiness Report Template

Please download the template above and return it via email to [email protected] as soon as possible.

You can view the template for the Placing Reliance RACI that is referenced in Appendix A of the MHHS-DEL2223 SIT Functional Participant Readiness Report below:   

SIT Functional Placing Reliance RACI