IN Brief:
- The Defence Investment Plan commits £298 billion over four years to UK capability and industrial capacity.
- GCAP, collaborative aircraft, uncrewed systems, and the Hybrid Navy will increase demand for digital engineering.
- Delivery depends upon controlled requirements, software assurance, integration, verification, validation, and sovereign engineering skills.
Expleo has welcomed the UK Defence Investment Plan’s emphasis on software-defined, autonomous, and connected systems, while identifying digital engineering and assurance as central to delivering the funded programmes.
Published by the Ministry of Defence and HM Treasury on 30 June, the plan sets out £298 billion of investment over four years, including an additional £15 billion between 2026–27 and 2029–30. Core NATO defence spending is expected to reach 2.7% of GDP from 2027–28, with the wider programme projected to support nearly 60,000 additional direct and indirect jobs by the end of the decade.
Major commitments include £8.6 billion for the Global Combat Air Programme, £300 million for Collaborative Combat Aircraft, and more than £5 billion for drones and uncrewed systems. Funding will also begin work on the Hybrid Navy, combining crewed ships, autonomous platforms, communications, sensors, software, and command systems.
“This is a welcome and much-needed blueprint from Government, with real commitment behind it,” said Jonathan Taylor, incoming UK managing director at Expleo. “Across aerospace and maritime, the plan sets out a clear strategic direction that hinges on software-defined, connected and autonomous systems. The task now is delivery, and that will be the hard part — the defence sector will need to work together to deliver these programmes safely, securely and at pace.”
Although the plan will increase demand for physical manufacturing, much of the engineering work begins before hardware reaches a production line. Requirements must be defined, interfaces allocated, models controlled, hazards assessed, and test evidence planned while systems remain digital enough to change economically.
The production line begins inside the model
Digital engineering connects requirements, architecture, design, simulation, manufacturing, test, and support information through a controlled technical environment. When those links are maintained, interface conflicts can be exposed before metal is cut, while the consequences of a design change can be traced across safety, performance, cost, manufacturing, and maintenance.
Autonomous systems place particular pressure on that discipline because a collaborative aircraft or uncrewed vessel is defined as much by software, data, communications, and behaviour as by its airframe or hull. Physical configuration cannot be qualified separately from the code controlling navigation, payloads, decision support, and interaction with crewed platforms.
Manufacturers therefore need a digital thread capable of following each configuration into production. The parts fitted to a platform, software loaded during acceptance, calibration data, approved deviations, and test results must remain linked. Without that control, two outwardly identical systems can enter service with different performance or behaviour.
Verification and validation also need to begin earlier. Verification establishes whether a system has been built against its requirements, while validation determines whether those requirements produce a capability suitable for its intended use. Autonomous platforms complicate both because behaviour can vary with data, environment, software baseline, and interaction with other systems.
“The engineering work behind these programmes is changing,” Taylor said. “More software, more autonomy and more integration between systems means more work upfront on requirements, interfaces, testing and assurance. That is why digital engineering is so important to programmes like the Hybrid Navy. Once these systems are in service, there can be no grey areas on safety or security.”
A Hybrid Navy will require crewed ships to command or cooperate with several uncrewed surface, air, and underwater systems supplied by different manufacturers. Each platform needs compatible data formats, communications, timing, navigation, cyber protection, and rules governing control transfer. Updating one component may affect certification and assurance across the wider force.
Shipyards and factories need digital information in a form suitable for production rather than design review alone. A sophisticated systems model offers limited practical value if fabrication drawings, cable schedules, software loads, manufacturing tolerances, and acceptance procedures remain disconnected.
Smaller suppliers face a proportionally greater burden because they may not use the same software, security systems, or configuration tools as prime contractors. Bringing them into a digital enterprise requires affordable access, common standards, training, and commercial terms that recognise the cost of compliance.
The funding-to-production gap is already visible in efforts to accelerate defence procurement and improve SME access. Faster contracting can remove administrative delay, but it cannot eliminate the engineering evidence required for weapons, autonomous behaviour, or safety-critical software. Evidence must be generated more efficiently rather than omitted.
Sovereign capability becomes especially important when systems require urgent modification. Britain may rely on international partners for hardware and software, yet operational independence requires enough domestic knowledge to understand interfaces, test changes, investigate faults, and maintain assured configurations.
GCAP illustrates the depth of that dependency, with electrical power, propulsion, sensors, software, and thermal management being designed as an integrated system. Its high-output power and propulsion architecture will determine how much sensor, computing, and electronic-warfare capability the aircraft can support during service.
Software-defined platforms also alter through-life manufacturing. Replacement components, repaired modules, and upgraded payloads must remain compatible with changing code, while production and maintenance staff need controlled access to current digital baselines. A physical spare that cannot accept the approved software configuration may be unusable.
The £298 billion plan gives programmes greater financial certainty, but funding does not automatically create verified designs, qualified suppliers, or accepted systems. Digital engineering can shorten the route by finding defects earlier, preserving traceability, and allowing factories to build against controlled information.
Britain’s delivery challenge is to use those methods without allowing digital process to become another administrative layer. Models, assurance, integration, and validation must support engineering decisions and repeatable production, turning funded programmes into systems that operate together reliably beyond the test environment.
