In April, I argued that readiness cannot wait for the Defence Investment Plan. On 30 June, after a year of delay and two ministerial resignations, the plan finally arrived: £298 billion of committed investment over four years, a step up to 2.7% of GDP by 2027, a clear signal for defence to move into the delivery era.
One month on, now that the dust has settled, my view is that the real challenge is not the scale of the investment, but how effectively it is converted into operational readiness. Most of the public conversation about defence investment takes place at programme level, mainly what is being bought, and when. However, most of the friction that determines whether the UK converts £298 billion into warfighting readiness sits in the space between the industrial ecosystem and the operational front line.
As the sector moves from reliance on a small number of highly sophisticated platforms towards greater volume, faster availability and more adaptable capability, control of supply becomes a strategic imperative. The UK cannot deliver at pace unless materials, components and equipment are visible, available and able to move through the system when needed.
Without effective control of supply, readiness will not be achieved.
Those in the sector know that resilience, availability, readiness and pace are the four pillars to describe the future of UK defence capability. We also know the limitations of historic approaches built around stockpiling spare parts and equipment, which are neither financially nor operationally sustainable.
Operational capability is not created at the point of purchase, it is created when the right item is in the right place, at the right time, with assurance of its condition and status. An organisation can buy the spares, the components and the equipment it needs and still find capability unavailable, because the item cannot be located, arrives late, or sits against inventory data nobody quite trusts. Readiness, for every CNI site and facility, every operational support service, every submarine, ship and aircraft, depends on people, materials, inventory, vendor management, information and infrastructure operating as one interconnected system, not as separate workstreams reporting up separate lines, each optimising for itself.
This is a lesson other sectors learned before defence had to. Energy and civil nuclear both operate under the same conditions defence now faces at scale: complex assets, dispersed sites, unforgiving consequences for failure. What distinguishes the organisations that cope well from those that don't is rarely the sophistication of their procurement. It is whether they treat control of supply as a discipline in its own right, engineered and governed deliberately, rather than an incidental output of buying well.
Control of supply is the strategic enabler of critical infrastructure programmes. At ASCO, we frame this discipline around five capabilities:
- Visibility - knowing what exists, and where.
- Availability - knowing what is actually ready to use, not just in stock.
- Flow - coordinating movement so materials arrive when and where they're needed.
- Assurance - trusting that the data describing all of the above is accurate.
- Control - knowing when to intervene before a small delay becomes a missed milestone.
The operational backbone behind the investment
A £298 billion plan can provide funding and direction, but it cannot create operational control on its own. The control is the difference between a well-funded programme and a congested dockyard or between a committed budget line and a submarine waiting on a part that technically exists somewhere in the system, just not where it happens to be needed.
The future is not simply more warehouses, more inventory, or better procurement. It is better control.
The Defence Investment Plan gives industry the clarity it has been requesting. It does not dissolve constraints already embedded in the delivery system, constraints that predate the plan and will outlast the political cycle that produced it. That work was available to begin before publication. Now that the plan exists, there is no reason left to wait.
The organisations that treat control of supply as core infrastructure to their delivery, will be the ones that deliver capability at the pace demanded. The rest will still be looking for their parts.