MJA has been awarded a three-year framework for Sizewell C, with a starting date of 21 September 2026, to provide senior commercial resources for Target Outturn Cost (TOC) assurance. The framework and evolving task-order programme focuses on earthworks and enabling works proposed by Civils Work Alliance members first, alongside a planned full Line of Defence review of the Alliance Services TOC. With detailed organizational compliance reviews targeted thereafter as we provide ongoing assurance support to this UK critical capital project.

Our role combines rigorous commercial challenge with senior stewardship of enterprise adoption across the Lines of Defence. Acting as a critical friend, we will test the evidence behind cost and commercial proposals and the organisational arrangements that produce them. The purpose is to help the Owner make informed decisions and support the assurance chain to investors and funders, including HM Government.

Our critical friend approach combines senior experience, constructive engagement and a willingness to challenge assumptions. Working closely enough to understand the delivery context, we will ask difficult questions, test explanations against evidence and present findings that leaders can act on. The role is intended to improve the quality of decisions while leaving accountability with those responsible for making and implementing them.

This approach is grounded in established infrastructure practice. Government cost-estimating guidance recommends review panels, independent assurance or a critical friend approach, with expertise tailored to the project. HS2’s Learning Legacy also records the use of an embedded specialist team to provide timely challenge on enabling works. These precedents inform the method; they do not imply an identical assurance mandate or results at Sizewell C. [1, 2]

For MJA’s evolving assignments, broad organisational testing will examine how governance, responsibilities, capability and information support commercial decisions. The proposed method combines review of records with discussions across organisational boundaries, testing whether the stated arrangements operate in practice. Emerging issues can then be explored with the relevant teams and translated into evidenced findings and proportionate recommendations.