For decades, just-in-time (JIT) inventory management was the default operating model for mid-market importers. The logic was straightforward: hold minimal stock, rely on predictable ocean freight, and reduce warehousing costs. That logic is now under sustained pressure from a structural shift in container shipping reliability.
Port congestion, measured by indices such as the Freightos Baltic Index and the Port of Los Angeles dwell-time data, has become a persistent feature of global trade rather than a temporary disruption. For mid-market importers — firms that lack the bargaining power of multinationals and the flexibility of large-scale warehousing — the implications are commercially significant.
What Changed
The Port Congestion Index, a composite measure of container ship waiting times, berth occupancy and container dwell times at major global ports, has remained elevated since the pandemic-era supply chain crisis. Although peak congestion levels of 2021-2022 have eased, the index has not returned to pre-2020 baselines.
Key structural factors include:
- Labour shortages: Dockworker and truck driver availability remains constrained in North American and European ports, slowing container movement.
- Infrastructure bottlenecks: Many ports have not expanded capacity to match post-pandemic trade volumes. The Port of Rotterdam, for example, has operated above 85% capacity utilisation for several quarters.
- Vessel bunching: Carriers have consolidated services, leading to irregular arrival patterns that overwhelm terminal capacity during peak periods.
- Geopolitical rerouting: Red Sea disruptions and Panama Canal draft restrictions have forced vessels onto longer routes, causing schedule deviations that propagate congestion at downstream ports.
These factors are not cyclical in the traditional sense. They represent a new baseline of reduced schedule reliability. According to Sea-Intelligence, global schedule reliability has stabilised at around 55-65%, compared to 75-80% before 2020.
Why It Matters
For mid-market importers, the shift from predictable to unpredictable ocean freight undermines the core assumption of JIT inventory: that goods will arrive on time, every time.
When a container is delayed by two to four weeks, the consequences cascade:
- Stockouts: Retailers and manufacturers lose sales. A mid-market electronics importer, for instance, may face lost revenue equivalent to 5-10% of quarterly turnover during a prolonged delay.
- Expediting costs: Air freight or premium rail alternatives can cost three to five times ocean freight, eroding margins.
- Customer penalties: Contracts with large retailers often include service-level agreements with financial penalties for late delivery.
- Working capital strain: Unexpected inventory holding periods tie up cash that would otherwise be deployed elsewhere.
The commercial impact is not uniform. Importers of high-value, low-bulk goods (e.g., electronics, pharmaceuticals) can more easily absorb air freight costs. Importers of low-margin, high-volume goods (e.g., furniture, apparel, basic consumer goods) face a more acute margin squeeze.
Commercial Impact
Mid-market importers are responding by adjusting inventory strategy. The emerging model is a hybrid: "just-in-case" buffers layered onto JIT principles.
Specific commercial adjustments include:
- Safety stock increases: Importers are raising safety stock levels from 2-3 weeks to 4-6 weeks of cover, according to supply chain surveys by the Institute for Supply Management.
- Diversified port strategies: Rather than relying on a single gateway port, importers are routing containers through multiple ports to spread congestion risk. This increases inland logistics complexity but reduces the probability of total disruption.
- Longer lead times in planning: Procurement cycles are being extended by 2-3 weeks to account for schedule variability, which shifts the timing of purchase orders and supplier negotiations.
- Warehousing investment: Some mid-market firms are leasing additional warehouse space, particularly near major consumption hubs, to hold buffer inventory. This increases fixed costs but provides resilience.
The net effect is a structural increase in inventory carrying costs. For a mid-market importer with annual turnover of £50 million, a shift from 3 weeks to 6 weeks of inventory cover could increase warehousing and financing costs by £200,000 to £400,000 per year, depending on product value density.
Risks / Unknowns
The shift away from pure JIT is not without its own risks.
- Over-correction: If port congestion eases unexpectedly, firms holding excess inventory may face write-downs or discounting pressure, particularly in categories with short product life cycles such as fashion or consumer electronics.
- Capital allocation: Increased inventory ties up working capital that could otherwise be used for growth investments, marketing or R&D. For capital-constrained mid-market firms, this trade-off is material.
- Supplier relationships: Longer lead times and larger order quantities may strain relationships with suppliers who are accustomed to smaller, more frequent orders. Re-negotiating terms takes time and may result in higher unit costs.
- Data quality: The effectiveness of buffer inventory depends on accurate demand forecasting. Many mid-market importers lack the data infrastructure to forecast with precision at longer horizons, increasing the risk of overstocking or understocking.
Unknowns include the trajectory of port infrastructure investment, the potential for labour automation to improve throughput, and the impact of nearshoring trends on container shipping demand. If more manufacturing moves closer to end markets, the pressure on ocean freight reliability may ease, but this is a multi-year trend with uncertain pace.
FY Outlook
Over the next 12 to 18 months, the FY Times expects port congestion to remain above pre-2020 levels, driven by structural capacity constraints and ongoing geopolitical disruptions. Mid-market importers should plan for continued schedule unreliability.
Three scenarios are plausible:
- Gradual improvement (40% probability): Port infrastructure investments in the US, Europe and Southeast Asia begin to take effect, and labour markets stabilise. Schedule reliability rises to 70-75%. JIT models become partially viable again, but with higher safety stock buffers than pre-2020.
- Persistent congestion (45% probability): Current conditions persist. The hybrid inventory model becomes the new normal. Mid-market importers that have already adjusted will have a competitive advantage over those that have not.
- Deterioration (15% probability): A new geopolitical shock or labour disruption pushes congestion to 2021-2022 levels. JIT models become unviable for all but the most agile, high-margin importers. Air freight and nearshoring accelerate sharply.
Conclusion
The era of predictable, low-cost ocean freight is not returning to its pre-2020 state in the near term. Mid-market importers that continue to rely on pure JIT inventory models are exposed to material financial risk from stockouts, expediting costs and customer penalties.
The commercially rational response is to adopt a hybrid inventory model: maintain JIT principles for high-turnover, predictable SKUs while building buffer stock for critical, long-lead-time items. This requires investment in warehousing, forecasting and supplier collaboration, but the cost of inaction is likely higher.
For founders, operators and supply chain executives, the key question is no longer whether to hold more inventory, but how much, where, and at what cost. The answer will vary by sector, margin structure and customer concentration, but the direction of travel is clear.
Source notes: This analysis draws on publicly available data from Sea-Intelligence, the Freightos Baltic Index, the Institute for Supply Management, and port authority reports from Los Angeles, Rotterdam and Singapore. No proprietary or embargoed data was used. All market claims are framed as estimates or probabilities based on published trends.
