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Just-in-time manufacturing has now failed at scale twice in five years. In 2021, Ford lost production of over a million vehicles because tier-two chip suppliers ran dry and nobody had mapped the dependency.

In 2026, ship transits through the Strait of Hormuz collapsed by more than 95 percent within weeks, and the companies most exposed were, in many cases, the same ones that were most exposed in 2021.

The first failure was explained away as a once-in-a-century event. The second one removes that excuse.

JIT Did Not Fail Because of Bad Execution. It Failed Because Its Core Assumption Was Wrong.

Just-in-time is not a flawed model in isolation. It is a model built on a specific assumption: that supply chains are fundamentally stable, transit times are predictable, and the geopolitical infrastructure underpinning global trade does not experience catastrophic failure.

The 2020s have invalidated that assumption four times in six years:

• 2020: Covid disrupted manufacturing and logistics globally
• 2021: The Ever Given blocked the Suez Canal for six days, costing an estimated 400 million dollars per day in delayed trade
• 2023: Houthi attacks disrupted Red Sea shipping from late in the year
• 2026: The Strait of Hormuz closed in what the IEA described as the largest supply disruption in the history of the global oil market

Four major supply chain shocks in six years is not a series of tail events. It is evidence that the operating environment itself has changed. JIT was designed for a world that no longer reliably exists.

Why Companies Rebuilt Lean After 2021, and Why That Decision Was Rational

The response after the Covid disruption was genuine. Resilience became a board-level priority. Supplier mapping exercises ran across industries. Dual sourcing was explored. Buffer stock strategies were discussed seriously and with urgency.

Then, over the following eighteen months, lean crept back. Not because companies forgot the lesson, but because the incentive structure that governs supply chain decisions had not changed. CFOs are measured on working capital efficiency.

Supply chain leaders who maintain strategic buffer stock are asked to justify the carrying cost in every stable quarter. The margin pressure to restore efficiency is constant and immediate. The risk of not having resilience is intermittent and distant, until it is not.

This is not corporate irrationality. The leader who builds a buffer that never gets used looks inefficient. The leader who removes the buffer and disruption arrives looks unlucky. Those two outcomes are not treated symmetrically in most organisations. That asymmetry is the structural reason lean keeps returning after every shock.

The reason JIT keeps coming back after every crisis is not that companies fail to learn. It is that the incentive structure rewards the behaviour that creates vulnerability and penalises the behaviour that prevents it.

What the Hormuz Crisis Is Showing About the Companies That Actually Changed

There is a visible performance difference in how companies are handling the current disruption, and it correlates strongly with whether they genuinely redesigned their supply chains after 2021 or only said they would.

Companies managing with confidence built tiered inventory strategies rather than blanket buffers: strategic stock on inputs with long sourcing tails, limited alternatives, or single-source dependencies, and leaner positions on commodity inputs with multiple qualified suppliers.

They qualified alternative sources before they needed them, a process that takes six to eighteen months for precision inputs. They built route optionality into logistics arrangements, so that Cape of Good Hope rerouting is an additional cost rather than a production-stopping event.

Companies that reverted to pure lean are now doing in emergency mode what the first group did in advance: sourcing alternatives, building buffer, and paying premium prices for both. The Supply Chain Digital expert panel during the Hormuz crisis noted that companies getting it right treat resilience as a prioritisation problem.

High-exposure freight gets protected. Flexible freight gets optimised. That distinction requires an architecture built before the disruption, not improvised during it.

“Add Buffer Stock” Is the Wrong Prescription on Its Own

The instinct after every supply chain disruption is to hold more inventory. That instinct is partially correct and, on its own, unsustainable.

A blanket buffer stock policy does not survive the next CFO review in a stable period. Carrying costs are visible and immediate. The risk those buffers protect against is hypothetical until it is not.

Without a clear framework for which inputs warrant strategic buffer, the policy erodes from the outside in, starting with the buffers that look most expensive and ending with the ones that matter most.

The right prescription is a tiered inventory architecture grounded in a genuine vulnerability assessment. An input warrants strategic buffer when it meets all three of the following criteria:

• A single dominant source or geography with no credible short-term alternative
• A qualification timeline longer than six months to onboard a replacement supplier
• A direct production consequence if supply is interrupted for more than two to four weeks

Inputs that do not meet all three criteria can remain lean without material risk. Building that architecture and defending it through stable periods requires sustained operational ownership, not a policy document.

Roland Berger stated it directly in their April 2026 analysis: even if disruptions in the Strait of Hormuz were resolved tomorrow, companies must continue to respond proactively, because a return to normal operations will not be immediate.

Why Resilience Does Not Stick Without the Right Leadership Owning It

Supply chain resilience is not a policy decision. It is a continuous operational and financial trade-off that needs to be made, defended, and maintained by someone with the authority and credibility to do all three.

The leaders who made resilience stick after 2021 share a specific capability. They understood the financial language well enough to defend buffer investments to CFOs and boards in stable periods, and the operational language well enough to build the right architecture in the first place.

Most organisations have one or the other. The leaders who have both are the ones who navigated the full cycle: recognition, response, rebuilding, and holding the line when efficiency pressure returned.

KPMG’s 2026 assessment is explicit: supply chain disruption is structural, not cyclical. Planning for volatility is now the baseline. That baseline requires supply chain leadership built for disruption as a permanent operating condition, not an exceptional one.

CE Interim deploys experienced supply chain and interim operations executives who have run this full cycle within 72 hours. The value they bring is not just the knowledge of what to build. It is the institutional credibility to defend it when the quarterly margin review arrives and lean starts to look attractive again.