When tariffs break the assumptions: How interim leaders help supply chains regain control
An interview with David Booher (USA) and Diederik Ising (Switzerland); initiated by IMW partners Pierina Tánno (Top50, Switzerland) and Pamela Wasley (Cerius Executives, USA)
For years, many supply chains were designed around one dominant logic: optimise for cost in a world that felt increasingly predictable. Global networks became smoother, lead times became more reliable, and the “lowest cost provider” mindset became standard practice across industries.
Today, that confidence is harder to defend. Tariffs and geopolitical uncertainty have introduced a new kind of volatility. For many organisations, this is not simply about absorbing higher costs. It is about questioning assumptions that once looked rational, and redesigning supply chains to perform under pressure. That shift is particularly acute for small and mid-sized companies, where time, resources, and specialist capability are limited, and where every strategic choice can materially affect the future of the business.
David Booher brings a US perspective shaped by more than three decades in industry across wire and cable, plastic packaging and consumer products. In his last corporate role he led end-to-end supply chain responsibilities for a $1.7 billion division of a multinational. Today he supports companies in transition and transformation through interim assignments, often stepping in when organisations need to stabilise, regain control, and build a platform for growth.
Diederik Ising brings a European perspective grounded in two decades in consumer goods, with experience in manufacturing, finance and supply chain transformation. He has worked on large transformation programmes for companies including Unilever, Adidas and Carlsberg, and later led digital manufacturing transformation initiatives within Danone. Based between the Netherlands and Switzerland, he now focuses on SME clients through an advisory model designed to lower the barrier for smaller companies to access senior expertise, and to accelerate decision-making and execution.
A recurring theme in their conversation is that supply chain decisions are always a balancing act. In stable times, that balancing act is easier to manage and easier to simplify. In volatile times, it becomes a leadership test.
As David explains, the core trade-off is between product cost, service level and inventory investment. In the years when global trade felt stable, many companies tilted heavily toward cost optimisation. Over time, global networks became so reliable that resilience and agility were treated as secondary concerns. That approach works, until the conditions that made it work are disrupted.
In David’s view, the recent decade has delivered multiple disruptions significant enough to reset the baseline. Tariffs on China were an early signal. COVID exposed the fragility of networks designed for efficiency rather than adaptability. More recent tariff pressure and broader geopolitical uncertainty have reinforced the message that yesterday’s optimisation model is no longer sufficient.
His conclusion is direct: “You can no longer just cost optimise and assume a less than agile supply chain. You now have to do the work to make sure you’re both resilient and agile.”
From a European viewpoint, Diederik recognises that duties and tariffs have always been part of global business, but he emphasises that what has changed is the unpredictability and the strategic ripple effect. Companies are asking themselves not only how to manage the immediate impact on landed cost, but also how dependent they want to remain on one market, one route, or one set of assumptions about the future.
He sees European companies thinking in two directions at once. On the one hand, some explore diversification, shifting part of their commercial focus away from the US where possible. On the other hand, many recognise that volatility is not unique to one country or one administration. The more strategic question is how to design a supply chain that can absorb shocks, shift routes and adjust operating models without collapsing into panic or paralysis.
Diederik captures this longer-term logic clearly: “In the long term, I need to have a solution for this because now it’s the US. Tomorrow it can be China.”
The conversation turns practical when both speakers describe what organisations can actually do, and what tends to make the biggest difference in the shortest timeframe. David points to areas where companies often underestimate the leverage they still have, especially when they treat tariffs as a blunt instrument rather than something that interacts with the detail of classification, contracts and network design. He highlights tariff engineering as a short-term lever, where companies examine the HS codes they use and the way products are classified. With the right trade expertise, that detail can materially affect exposure and cost.
He also shares a concrete example from a plumbing company impacted by the first wave of China tariffs. A key step was reducing SKU complexity to create clearer volume aggregation, then rebidding and reengineering parts of the supply base. The result was measurable and fast relative to the size of the issue.
His takeaway is worth keeping as a proof point for SME owners who assume they have no room to manoeuvre: “We were able to save 10% on reducing tariffs by aggregating and by rebidding and by reengineering.”
Diederik frames the same idea through a different lens. Many of the analytical capabilities needed to understand exposure and evaluate options are standard practice in large corporates, but smaller companies often cannot justify building those capabilities internally. In that context, the value of interim leadership is not just advice, but bringing an approach and a way of working that can be deployed rapidly. That begins with quick diagnostics, moves into scenario evaluation, and then becomes execution support so the chosen path is implemented rather than parked in a slide deck. In his experience, this is where SMEs benefit most because they need impact within months and sometimes within weeks.
This is also where the conversation draws a sharp line between consulting and interim leadership. Supply chain redesign usually requires uncomfortable, practical work. It can mean renegotiating contracts, re-opening freight terms, rethinking who carries tariff responsibility, putting providers out for bid, changing governance, and mobilising teams that have not done this kind of work before. In smaller companies, that can be intimidating. People may be loyal to long-standing partners, uncertain about negotiation, or hesitant to challenge established routines. Both speakers argue that interim leaders add disproportionate value precisely because they embed during execution, not only during diagnosis.
David describes the mindset shift an interim leader helps create, especially when teams are asked to do things they have never done before: “When you become part of that organization as an interim, you’re directing the people to do processes and behaviors that they’ve never done before.”
Diederik adds that interim leaders often play a second role: challenging the status quo and countering internal narratives that have not been questioned in years. In many companies, there are biases about what is possible, what is too risky, or what cannot be changed because “we’ve always done it like this.” Interim leadership can help surface reality, define a clear baseline, and drive the organisation toward a result rather than a discussion.
This balance between structure and judgement comes back when they talk about playbooks. Yes, there are established methods for regaining control of supply chains, reducing exposure, and improving resilience. But no, this is not a copy-paste exercise. Methods must fit the organisation’s capacity, urgency and talent pool. Diederik describes interim management as both art and science, where the science is the fact-based approach and a disciplined methodology, and the art is experience, judgement and the ability to steer teams through distractions and complexity.
David uses a metaphor that makes the point memorable: “We’ve seen that movie before.”
That line becomes more concrete when he answers a follow-up question about what “seeing the movie” actually looks like in practice. He shares a lesson from the earlier tariff era. In a moment of crisis, anxiety rises and urgency can override methodical thinking. His team accepted a supplier’s plan to shift production from China to Vietnam as a major solution to the tariff problem. The plan made sense, but it did not deliver at the pace needed. Delays and ramp-up time created an eight-month stall. The lesson was not that Vietnam was the wrong option. The lesson was that relying too heavily on one path increases risk.
His point is about building options and parallel work streams rather than betting the business on one route: “What we failed to do… is being over reliant on one or two paths towards solution versus do the extra work to outline three or four paths and pursue them in parallel.”
Diederik adds his own “repeat movie” patterns. He has repeatedly seen companies centralise and globalise in search of simplicity and governance, only to later regionalise and localise again when agility and market proximity become more important. He has also seen cycles of outsourcing and attempted insourcing. Once a capability is outsourced, bringing it back is rarely straightforward because knowledge and routines have been lost. In other cases, proximity to demand and the cost of a missed sale outweigh small production cost advantages, which can change the economics of where and how a product should be made.
Underneath all of this sits a more human question: how do owners and leaders make decisions when the stakes are high and the future is uncertain. Both speakers emphasise trust first. Without trust, facts will not land and recommendations will not stick. But they also emphasise truth. Owners need clarity about how the company actually operates at ground level, not only how it is assumed to operate. David argues that interim leaders often discover a gap between leadership assumptions and operational reality, and that aligning on that baseline is the first real step toward good decision-making. From there, scenario thinking becomes meaningful, because the assumptions are shared and the numbers are credible.
The conversation closes with a practical emphasis on urgency. Some actions are low risk and can be initiated immediately, even before deeper strategic decisions are made. Understanding HS codes, reviewing logistics terms and tariff responsibility, and surfacing where contractual exposure sits can create breathing space. That breathing space matters because it buys time, and time creates options.
For IMW clients, the broader message is that today’s trade volatility is not only a supply chain problem. It is a leadership problem with operational consequences. Large companies may have internal teams to analyse, model and execute. SMEs often do not. Interim leaders bridge that gap by bringing proven methods, pattern recognition from prior disruptions, and the ability to execute with the organisation, while transferring capabilities so the improvements remain after the assignment.
If global trade has become less predictable, the companies that regain control will be those that know their own baseline, build options rather than single bets, and move early enough to create room for incremental, lower-risk decisions.