UK civil infrastructure programmes are where project controls earn their keep. Long programmes, complex multi-contractor interfaces, NEC4 compensation events and the scrutiny of public spending create an environment where weak planning, inadequate risk quantification and unreliable cost reporting have consequences that end up in the National Audit Office.

SOMA's infrastructure work is anchored in National Highways' RIS3 major projects portfolio, through AtkinsRéalis. We understand the NEC contract mechanisms that drive schedule and cost discipline, the NISTA (formerly the IPA) assurance requirements that apply to publicly funded works, and the reporting expectations of client programme directors who are accountable for spend.

Infrastructure is the broadest of SOMA's markets and the one where NEC4 expertise pays the heaviest dividend. The dominant client environments — Network Rail (CP7 covering 2024–29), National Highways (RIS3 for 2025–30, with RIS2 still in delivery on long-tail schemes), the Environment Agency capital flood and coastal programme, HS2 Limited and its tier 1 supply chain, and the regional Combined Authorities running major urban transport works — almost universally contract under NEC4 ECC, with Option C target cost on most major works and Option A on smaller packages. The controls function has to operate the contract's machinery (Accepted Programme, Compensation Events, Early Warnings, Defined Cost reporting) as the day-to-day reality, not as an occasional commercial topic. Add to that a long-cycle delivery pattern (RIS and CP funding settlements run on five-year cycles; AMP water programmes also five years; HS2 is decade-plus), and the controls function becomes the institutional memory of a programme that will outlast every individual delivery team it passes through.

The commercial scrutiny on infrastructure spend is heavier than on most sectors. HM Treasury's Green Book sets the appraisal standard, the Five Case Model governs business-case construction at each gateway, and NISTA (formerly the IPA) Gateway Reviews land at defined decision points for any programme on the Government Major Projects Portfolio. Recent NAO and PAC reports on infrastructure cost overruns have raised the bar on what counts as a defensible QRA submission — optimism bias adjustments per the Green Book Supplementary Guidance, P50/P80 confidence reporting, and a clearly evidenced risk register are now the floor rather than the ceiling. Where the controls function lets the programme down on infrastructure, it is almost always because the schedule, cost model and QRA were not built to talk to each other — three independent artefacts produced by three teams that never reconciled at gate. The deliverable is integration, and integration takes deliberate design from RIBA Stage 2 onward.

Delivery challenges in this sector

  1. NEC4 compensation event management

    NEC4 contracts create a continuous stream of compensation events that must be assessed, agreed and incorporated into the Accepted Programme. Without a disciplined process for keeping the programme current, the schedule quickly becomes a record of the past rather than a plan for the future.

  2. Multi-contractor interface management

    Large infrastructure programmes involve multiple main contractors with separate programmes that must interlock at interface events. Consolidated schedule and cost reporting that gives the client a reliable picture of the overall programme requires deliberate data model design and consistent controls standards across the supply chain.

  3. QRA for funding submissions and gateway reviews

    The HM Treasury Green Book requires optimism-bias and risk adjustment for major publicly funded projects, and reviewers commonly expect P50, P80 and P95 confidence levels. The QRA must be structured to withstand scrutiny from NISTA and from the spending authority. Getting this right at RIBA Stage 2 or 3 avoids expensive rework at sanction.

  4. Schedule logic integrity under delivery pressure

    As delivery pressure builds, there is a natural tendency to loosen the schedule logic — adding constraints to show a better completion date rather than fixing the underlying plan. Controls that maintain logic integrity and surface the real critical path are what prevent programmes from surprising their boards at review.

How SOMA approaches Infrastructure programmes

We work within the NEC4 framework as practitioners who understand the contract mechanics, not just the scheduling tool. Our QRA work is structured to support the Green Book's optimism-bias and risk-adjustment requirements. Our cost and EV reporting is designed to give client programme directors a reliable, early-warning signal — not a retrospective account of what went wrong.

Standards and frameworks

  • NEC4 (Engineering and Construction Contract)
  • HM Treasury Green Book
  • NISTA (formerly the IPA)
  • RIBA Plan of Work
  • AACE International — Total Cost Management Framework
  • CESMM4 (Civil Engineering Standard Method of Measurement)
  • SCL Delay and Disruption Protocol

Further reading

Methodology hub

Frequently asked

Infrastructure project controls — questions we get asked

Does SOMA understand NEC4 compensation events and their impact on the Accepted Programme?
Yes. Our planners understand the mechanism for incorporating compensation events into the Accepted Programme — the eight-week notification time bar (cl.61.3), the requirement to show the impact on planned completion, and the commercial consequence of failing to notify. We design schedule systems that make compensation event management systematic rather than ad hoc.
Can SOMA produce QRA that supports a Green Book business case?
Yes. We structure QRA models to support the Green Book's optimism-bias and risk-adjustment requirements — P50, P80 and P95 confidence levels where the funder asks for them, base estimate uncertainty separated from discrete risk events, and a report that explains the methodology clearly enough to satisfy a NISTA or spending authority reviewer. Our QRA work for National Highways is delivered through AtkinsRéalis.
Can SOMA help consolidate schedule and cost reporting across multiple contractors?
Yes. Integrated reporting across a multi-contractor programme requires a common data model, agreed WBS levels, consistent progress reporting conventions and a mechanism for rolling up without losing traceability. We design these systems at the start of programmes, and we take over and rationalise them mid-programme when they have grown organically and inconsistently.
At what project stage should SOMA be engaged?
Ideally at RIBA Stage 2 or 3, before the estimate and programme are fixed. Controls set up early — with a properly structured WBS, a logic-linked programme and a QRA-ready risk register — cost significantly less than controls retrofitted at Stage 4 when the pressure is on. That said, we also take over programmes mid-delivery and bring the controls up to standard as quickly as possible.

Working on a Infrastructure programme?

Most engagements start with a short call. We work out whether we're the right fit, then come back with a short scoping note — scope, duration, team, indicative cost.