From Supplier to Partner: When Customers See a Business That Way

Why “partner” is more than a friendly word

In proposals and on websites, the term is everywhere: “Your partner for …”. From the customer's point of view, it is usually meaningless. A buyer knows very well which suppliers they could replace and which they could not. This distinction has consequences: with interchangeable suppliers, they negotiate on price; with a few others, they plan together, share information, and look for solutions when things get difficult.

For a small business, the second role is tempting. It brings more stable revenue, less price pressure, and earlier involvement in the customer's projects. The guiding question of this analysis is: when do customers see a business as a fixed partner rather than an interchangeable supplier? To answer it, we first introduce the Kraljic matrix as a mental model from the purchasing perspective, then review what research knows about key suppliers, weigh two perspectives, and finally turn to what a business can influence itself.

You do not become a partner through the word in your proposal, but through your place in the customer's purchasing plan.

The mental model: the Kraljic matrix from the customer's view

In 1983, Peter Kraljic proposed in the Harvard Business Review that purchasing departments should not treat all procurement the same, but sort it by two questions. First: how strongly does this purchase affect the company's results, for example through cost, quality, or growth? Second: how great is the supply risk, meaning the danger that supply fails or can only be replaced with difficulty? This yields four fields with different purchasing strategies.

The model is over 40 years old and still widespread in purchasing departments. Fontes, Delke, Schiele, and colleagues (2025) compared the processes of 17 leading companies and found the Kraljic matrix still the dominant tool, albeit with differently defined axes. Anyone supplying such companies is therefore very likely to be sorted into one of these four fields.

For the guiding question, this is an important insight. In the model, the partner role is not a reward for good work but the consequence of a purchasing situation. A business offering a service the customer considers unimportant and easily replaceable lands in the non-critical field, even if it does excellent work. A business becomes a partner when its service matters for the customer's results and cannot be replaced at will.

What makes a key supplier: the findings

Many companies have significantly reduced their number of suppliers over the past decades. Ulaga and Eggert (2006) cite as an example a Sony program from 2003 that aimed to cut the number of suppliers for components and raw materials from 4,700 to 1,000. For providers, this means: they either become a key supplier or slip into the role of a backup supplier who gets only a small share of the business.

Ulaga and Eggert examined how suppliers in this situation can differentiate themselves. They first conducted in-depth interviews with purchasing managers at manufacturing companies in the US Midwest and then surveyed 400 senior buyers nationwide. Their framework is a two-by-three matrix: benefits and costs at three levels, namely the core offering, the sourcing process, and the customer's operations.

The result contradicts the common assumption that price matters most. The benefit side distinguished key suppliers much more strongly than the cost side. Service support and personal interaction had the strongest effect, followed by the supplier's know-how and its ability to speed up the customer's processes. Product quality, delivery performance, and costs were of moderate importance, price the least. The authors explain this with their sample: respondents were asked about suppliers already on the shortlist. Costs are the entry ticket; benefits decide first place.

The study concerns manufacturing companies in the US and suppliers of routinely purchased products. For a small service provider, the transfer is an assessment. But it is an obvious one: if you cannot win on price, you win through your work in the sourcing process and in the customer's operations.

Two perspectives: partnership as goal or as risk?

In favor of partnership is its stability. Morgan and Hunt (1994) showed that commitment and trust carry successful business relationships, as the guide setting up sales partnerships describes. A customer who sees a business as a partner involves it early in projects, shares plans, and seeks a joint solution when problems arise rather than a new provider. This reduces the effort for sales and negotiation and creates predictability.

Against an ill-considered partnership is mutual dependence. Those who adapt to a customer, adjust their own processes, and reserve capacity become harder to replace, but also more dependent themselves. The term “partner” is also sometimes used to make demands sound softer: longer payment terms, discounts for “our shared future,” services without compensation. The analysis customer concentration risk describes how high dependence shifts bargaining power to the customer.

I consider partnership a good goal with a few carefully chosen customers, not with all of them. A business should consciously decide with which customers it invests in the partner role, and there honestly check whether the customer invests too. A partnership into which only one side pays is a supply relationship with higher costs.

How a business can influence its role

The Kraljic matrix suggests that the role depends mainly on the purchasing situation. Still, a business is not entirely at its mercy. It can influence how important its service is for the customer's results and how hard it is to replace. Five levers follow from the findings.

1. Make the benefit visible to the customer

   Show in figures what your service achieves in the customer's business: less downtime, less scrap, faster processes. How to calculate this is described in the guide expressing customer value in euros.

2. Relieve the sourcing process

   In the study, service and personal interaction were the strongest differentiators. A fixed contact person, quick answers, complete documents, and proactive alerts reduce purchasing's effort.

3. Contribute expertise

   Offer to think along early on the customer's projects, for example when planning a new installation or process. Those involved early help shape the requirements.

4. Invest deliberately in a few customers

   Choose the two to five customers for whom your service actually has a high profit impact and look after them with a dedicated plan, as described in the guide key account management for mid-sized companies.

5. Check reciprocity

   Once a year, check whether the customer invests too: planning data, fair price adjustments, reliable payment, recognition of additional services. If this is persistently missing, adjust your effort.

The first lever deserves special attention. Many small businesses deliver benefits the customer does not see, because they arise in the customer's processes and do not appear on the invoice. Naming this benefit shifts the business in purchasing's perception from the non-critical or leverage field toward the strategic field. Why the extras often count more than the product is described in the essay service as a differentiator.

Limits and transfer

Three limitations belong to this analysis. First, the Kraljic matrix describes how the purchasing departments of larger companies think. Small customers without their own purchasing department often decide more personally and less systematically, though the basic logic of importance and replaceability applies there too. Second, Ulaga and Eggert's findings come from US manufacturing and rest on buyers' assessments. Third, both approaches measure how customers see suppliers, not whether a partnership pays off for the supplier. Every business has to do that calculation itself.

• For the most important customers, it has been estimated which field of the Kraljic matrix the business is in.
• The benefit of your own service in the customer's business is described in figures.
• Every important customer has a fixed contact person with a short response time.
• It has been consciously decided with which customers the business invests in a partnership.
• Once a year, it is checked whether the customer also invests in the relationship.
• No single customer accounts for more than a quarter of revenue.

Conclusion: when customers see a business as a partner

To answer the guiding question: customers see a business as a fixed partner when its service is important for their results and hard to replace, and when it creates value beyond price and quality, above all through service, personal contact, and expertise that improves the customer's processes. Costs get a provider onto the shortlist; benefits make it the key supplier.

The partner role is therefore not a label you give yourself, nor a goal for every customer relationship. It pays off with a few customers in which both sides invest. Where only the supplier invests, it is more honest and cheaper to remain a good supplier.