Category management in a factory: cutting spend by process rather than by ledger code

Group by how the part is made, not by what it is called

The useful boundary is the supply market. Machined components, aluminium die castings, injection moulded parts, sheet metal fabrication, wire harnesses, printed board assemblies and surface finishing each draw on a distinct population of suppliers with distinct equipment, materials and constraints. A category defined that way lets one person build real knowledge of who can do the work, what drives cost, and where capacity sits. A category defined as electrical components or purchased parts spans several unrelated supply markets and nobody in it can hold expertise across all of them. Draw the boundary where the supplier population genuinely changes, and the rest of the structure follows.

What a category strategy has to contain to be usable

A document that lists spend and names a saving target is not a strategy. A usable one describes the supply market and who is in it, what genuinely drives cost in this process family, how your current supplier set is positioned against capacity and risk, what the specification standardisation opportunity is, what the sourcing approach will be and why, and what would trigger a change of approach. It should be short enough to be read by the plant and specific enough that another buyer could pick it up. Most importantly, it should be revisited when the product changes, not annually by calendar.

The category manager and the plant buyer are different jobs

One holds a supply market across sites and time; the other holds material flow at a site today. Combining them means the category work never happens, because the schedule always wins. Separating them without defining the interface means the plant discovers a supplier change from a delivery note. The workable arrangement gives the category manager ownership of supplier selection, agreements and development, and the plant buyer ownership of scheduling, expediting and day-to-day resolution, with a standing route by which persistent operational problems become category evidence rather than private frustration. Without that route, the category strategy drifts away from what the plant experiences daily.

Standardisation is the largest lever a category holds

Across a mature product range, the same function is usually served by many similar parts specified independently by different engineers at different times: fasteners in dozens of near-identical variants, several bearings that could be one, a handful of finishes that differ for no current reason. Consolidating them reduces the supplier set, increases the volume behind each part, cuts inventory locations and simplifies qualification. The work is engineering work that procurement instigates, and it requires someone with the authority to close old part numbers. It is slower and more valuable than any negotiation the category will run.

Reviewing a category when the product changes underneath it

Categories decay quietly. A new product introduces a process family nobody owns; a redesign moves volume from castings to fabrications; a plant closure changes the geography; a supplier is acquired and the market structure shifts. The trigger for review should be an event, not a date. Tie the category to the product roadmap so an approaching design change prompts reassessment while there is still time to influence the specification, and check periodically that the category boundaries still describe distinct supply markets rather than a structure inherited from a product range that no longer exists.

Frequently asked questions

How many categories should a mid-sized manufacturer have?

Few enough that each has a genuine owner with time to build market knowledge. A structure with more categories than people is a filing system rather than a management approach. Start from the process families that account for most of the direct material spend, give each a named owner, and group the long tail into a residual category managed transactionally. Add categories only when spend and complexity justify dedicated attention, and merge them back when a product change removes the reason they existed.

Should indirect and maintenance spend be managed as categories too?

Yes, but with different methods and expectations. Indirect and maintenance purchasing typically involves many small transactions, many requesters and specifications set by whoever happens to be ordering. The lever there is usually consolidation, framework agreements and reducing transaction handling rather than deep supply market analysis. Treating it with the same intensity as a direct material category consumes effort disproportionately, while ignoring it entirely leaves a surprisingly large amount of uncontrolled spend and supplier count.

How does category management relate to what engineering decides?

Category work sets the frame within which engineering choices are made, and engineering choices determine what the category can actually achieve. A category manager who knows the supply market can tell a designer which material and which tolerance widen the supplier pool, and can maintain preferred component lists that reflect availability rather than habit. Without that connection, the category is limited to negotiating parts that were already specified in a way that constrains who can make them.