Search “inventory control” and the first ten results are written for someone running a warehouse, a shop, or a Shopify store.
If you build equipment, devices, or machinery for a living, that advice mostly doesn’t apply. Your stock problem isn’t aisle layout or pick-path optimisation. It’s keeping 2,000 part numbers in sync with live production demand across half a dozen concurrent job cards, against a multi-level bill of materials that quietly changes every time engineering tweaks a design!
This post is for Operations Directors and MDs at 20-80 person SME equipment, device, and machinery manufacturers who already run their accounts on Xero, QuickBooks, or Sage 50, and whose stock is still held together by a spreadsheet and a senior assembler with a good memory. The term “inventory control” applies to you, but it means something specific, and it’s not what the generic guides describe.
In brief: Inventory control for an SME equipment manufacturer is the discipline of keeping stock levels accurate against live production demand, not against a shelf plan. The problem is demand-driven, multi-level, and tied to bills of materials rather than SKU velocity. The fix is a system where stock demand, procurement, and picking all run from one source of truth — which is how specialist MRPs like Flowlens, designed for SME equipment manufacturers, replace the spreadsheet without replacing the accounts package.
What inventory control actually means in a manufacturing context
Inventory control is the set of processes that keep your recorded stock levels accurate, your reorder decisions rational, and the right parts available at the moment a job card needs them. That definition is general enough to cover a Costco distribution centre and a Belfast switchgear assembler — but the mechanics could not be more different.
In retail and distribution, inventory control is a SKU-velocity problem. You’re optimising for storage cost, pick rate, and stock-to-sales ratio against a relatively flat demand curve. In manufacturing, it’s a demand-driven problem. A sales order for one finished product triggers a cascade of component needs via the bill of materials. A change to a sub-assembly cascades upward through every parent that uses it. You’re not managing stock against shelf plans — you’re managing it against live production demand that changes every time sales takes a call.
That distinction is why most of the “inventory control software” on the market doesn’t work for small manufacturers. It’s built for warehouses, where the questions are “how much of SKU 2451 is on the shelf” and “when do we reorder”. In a manufacturing business the questions are “do I have the parts to complete job 1874”, “which parts for job 1874 are already assigned to job 1862”, and “what do I need to order now to keep job 1891 on track for its June promise”.
The three inventory views an SME manufacturer actually needs
If a system can answer three questions at any moment, it gives you workable inventory control. The three views are:
- On-shelf — what is physically in the building, unassigned to any job
- Assigned-to-job — what is on the shelf but already committed to a specific open production order
- In-transit — what is on a purchase order to a supplier, with an expected arrival date
The mistake almost every spreadsheet system makes is treating on-shelf as the only number that matters. An engineer logs in, sees 40 of a part in stock, commits to a build, and doesn’t realise 36 of those 40 are already assigned to a job that’s halfway through assembly. The stock-out happens in week three of a build that was supposed to take four. Assigned-to-job is the view that prevents that failure, and it’s the view spreadsheets are worst at maintaining.
Why spreadsheet control runs out of road around 200 SKUs
Most SME equipment manufacturers limp along on spreadsheets until they hit two walls. The first is volume — somewhere around 200 active part numbers, with five or more concurrent jobs, the manual effort to keep the spreadsheet current exceeds the time anyone has. The second is the BOM problem: once you’re assembling products with sub-assemblies (which every equipment or device manufacturer is), a stock shortfall at level three of the BOM cascades upwards invisibly until assembly stops.
Spreadsheets don’t do multi-level BOMs well because they don’t do relationships well. A sub-assembly shortage has to be manually traced by a human who knows how the product is built. That human usually exists in one head, belongs to one person, and is the single biggest risk the operation carries. When that person is on holiday, production stops or errors compound.
Tim Morgan, MD of Cheshire-based all-terrain mobility manufacturer Mountain Trike, put the shape of the problem plainly: “Our all-terrain mobility products are made up of several sub-assemblies with their own bill of materials, and staying on top of the stock requirements has become a particular challenge.” That’s the wall. It’s the same wall for sensor makers, subsea equipment builders, LED lighting assemblers, and every other type of discrete manufacturer that Flowlens works with.
What good inventory control looks like in practice
A workable inventory control setup has six attributes worth evaluating in any system you consider:
- Multi-level BOMs with revision control, so changes in engineering don’t silently invalidate the plan
- A live assigned-to-job view, not just on-shelf, on every part
- Supplier lead times tied to each part, so reorder points reflect reality rather than a guess
- Stock movements captured at the point they happen — goods-in at the dock, picking at the job card, dispatch on the shipment
- Batch and serial number tracking where traceability matters
- Integration with your accounts package so financial stock valuation matches operational stock counts without rekeying
The last attribute is the one most small manufacturers underestimate. Your accountant’s stock valuation and your ops team’s stock count disagree almost every month in a spreadsheet-run business. Fixing that disagreement by making the operational system the source of truth — and letting it feed the accounts — is the whole game.
Where Flowlens fits in one paragraph
Flowlens is a cloud MRP built specifically for SME equipment, device, and machinery manufacturers of 1-100 people. It gives you the three inventory views on every part, multi-level BOMs with revision control, supplier lead time integration, and direct integrations to Xero, QuickBooks, and Sage 50 on the accounting side. Its role in an inventory control context isn’t just to replace the spreadsheet — it’s to make the system the master for stock demand generation, procurement, and picking or consumption. Every user and role contributes to the same dataset in the course of doing their normal work, which is what actually protects the integrity of the data.
Alan Rex, Operations Director at electrochemical gas sensor manufacturer DD Scientific, described what that shift felt like after they implemented Flowlens: “The stock forecast graphs have helped us with our planning too, it’s a clear indication of when we need materials versus the job card outputs.” The cultural shift usually follows the technical one. Julian, MD of distributor Halomec, puts the attitude that emerges in three words: “If it ain’t on Flowlens, it never happened.”
Conclusion
Inventory control for an SME equipment manufacturer isn’t the warehouse problem the generic guides describe. It’s a demand-driven, BOM-linked, production-coupled discipline — and spreadsheets stop keeping up somewhere around 200 active parts. The move that actually fixes it is making one system the master for stock demand, procurement, and picking, so the data stays right in the normal course of work rather than because one person is keeping it right.
FAQs
Is inventory control the same as inventory management?
In practice they’re used interchangeably, but strictly: inventory management is the broader discipline (what to stock, how much, where), while inventory control is the day-to-day accuracy of knowing what you actually have. Both matter for manufacturers, but inventory control is what fails first when spreadsheets run out of road.
Do I need a full MRP system to get inventory control right?
For SME equipment manufacturers with multi-level BOMs and concurrent production jobs, yes — a general-purpose inventory app won’t handle the BOM cascade or the assigned-to-job view. A specialist MRP like Flowlens, which integrates with Xero, QuickBooks, or Sage 50, covers the inventory side without forcing you to replace your accounts package.
How quickly can a small manufacturer move from spreadsheets to a proper inventory control system?
Flowlens typically gets SME equipment and device manufacturers fully operational in 2 to 16 weeks using a “Crawl, Walk, Run” methodology — starting with stock and parts, then layering in production, CRM, and service. First value usually lands in the first few weeks rather than at the end of a year-long project.
Want to see how an MRP built for equipment manufacturers handles your actual BOMs and stock? Start a free trial of Flowlens — the sandbox account lets you model your own parts, suppliers, and jobs before committing.
