Here’s a slightly uncomfortable thought. A good chunk of the money your factory loses this month won’t show up on any invoice.

There’s no bill for the hour a machine sat idle waiting for a first off check. No line on the P&L for the pallet of brackets nobody actually ordered. Nobody sends you a statement for the forty minutes your best setter spent hunting for a torque wrench that “lives” in a drawer it’s never in.

But you pay for all of it. Every single week.

And right now, I think that matters more than it has in a long time. UK manufacturers are paying the highest energy prices in the G7. Nearly nine in ten expect employment costs to keep climbing this year. A Make UK survey back in May found that almost every firm (98%) expects a real hit to profitability, and close to four in ten have already pushed investment back. You can’t do much about the price of gas. You don’t set the National Living Wage. What you can do is stop paying for things your customer never asked for.

That’s really all lean manufacturing is, once you strip away the Japanese vocabulary and the consultant slide decks. It’s a way of looking at your process and asking, for every step, “would the customer pay for this?” If the answer’s no, it’s waste. Taiichi Ohno, the engineer behind the Toyota Production System, grouped that waste into seven types. An eighth, unused talent, was added later as lean spread beyond Japan. Most people remember all eight with one handy word, DOWNTIME: Defects, Overproduction, Waiting, Non utilised talent, Transportation, Inventory, Motion and Extra processing.

I’ll be honest about something. The first time I sat down with a small fabrication business and mentioned lean, the owner laughed. “We’re twelve people in a unit in Walsall,” he said. “That’s for Toyota.” Fair enough, I thought. But by lunchtime we’d found a rack of finished parts that had been sitting there so long the job card had faded. He stopped laughing after that. Not because I’d said anything clever. He just saw it.

So this isn’t a theory piece. It’s a field guide. For each of the eight wastes you’ll get a plain description, a real example from the kind of factory you probably run, and something you can actually do about it. I’ve grouped them into four families, because that’s roughly how you’ll spot them on a normal walk round the floor.

The wastes hiding in your schedule: overproduction, inventory and waiting

These three are close cousins. In my experience, if you find one of them, the other two are usually standing just behind it.

1. Overproduction

Overproduction means making more than the customer needs or making it before they need it. Lean people often call it the worst waste of the lot, and I think they’re right, because it quietly creates most of the others. Extra parts need storing, moving, counting and, sometimes, scrapping.

Field example. A sheet metal shop gets an order for 40 brackets. The press brake is already set up and the materials on the bench, so the supervisor runs 200. “Saves a changeover next time,” he says. Sounds sensible. Except the customer changes the hole spacing four months later, and 160 brackets go in the skip. That’s material, energy, labour and machine time, all paid for twice. Once to make them, and once to throw them away.

What to do about it. Make to the order, not to the machine. If long changeovers are the reason you batch big, that’s the real problem to work on. A simple rule helps: nothing gets made without a customer order or an agreed stock level behind it. Write the rule down. Stick it on the press.

2. Inventory

Inventory is overproduction’s slower, sneakier sibling. Raw material, work in progress, finished goods, it’s all cash sitting on your floor. The usual rule of thumb is that holding stock costs somewhere between 20% and 30% of its value every year, once you add up space, insurance, handling, damage and the cost of the money tied up in it. Some careful benchmarking puts the real figure nearer 10% for well-run firms. Even at the low end, that’s not nothing.

Field example. A food producer I worked with bought a year’s worth of printed film to get a better unit price. Good deal on paper. Then the retailer changed the label design. Most of that film sat in storage… well, it did, until it went to landfill. And for eight months it took up space that could’ve held product.

What to do about it. Walk your stores and ask one question of every pallet: “when will this actually be used?” If nobody knows, that’s your answer. Set sensible maximum levels for your top twenty items and check them monthly. And be a little wary of bulk discounts. A 10% saving can be wiped out by one design change.

3. Waiting

Waiting is any time people, machines or materials are stood still because of something else. It’s the most visible waste on the floor, and oddly the one we get most used to.

The big, dramatic version is unplanned downtime. Research for Fluke found 68% of UK manufacturers had suffered it in the previous year. The headline cost figures in that study come from large plants, but an earlier Oneserve survey put the average UK manufacturer’s loss at around 49 hours a year, roughly 3% of working days. In a small factory, that’s more than a week of output. Just gone.

But honestly? The waiting I see most in smaller firms isn’t the big breakdown. It’s the little stuff.

Field example. A CNC operator finishes setting a job, then waits for the quality engineer to sign off the first part. The engineer’s in a meeting. Forty minutes later the spindle finally turns. That happens two or three times a day, across several machines. Nobody’s done anything wrong, exactly. The process just has a queue built into it.

What to do about it. Track waiting for one week. A tally sheet taped to each machine is plenty: what were you waiting for, and for how long? You’ll probably find two or three causes cover most of it. Train setters to do first off checks against a clear standard. Have the next job’s material and tooling ready before the current one finishes. And get basic preventative maintenance right before you even think about buying clever sensors.

The wastes on the move: transportation and motion

People mix these two up all the time, and to be fair, the line is a bit blurry. Here’s how I think of it. Transportation is moving the product. Motion is moving the person.

4. Transportation

Every time a part goes on a forklift, a trolley or a pallet truck, you’re paying for it. Fuel or charging, labour, the truck itself, and the risk of a dropped crate. And the customer gets nothing for any of it. A part that’s travelled 500 metres isn’t worth a penny more than one that’s travelled five.

Field example. A plastics moulder grew the way lots of UK firms grow, one unit at a time. Moulding ended up in one building, assembly in the next, and packing in a third across the yard. When someone finally traced a single product’s journey with a trundle wheel, it covered just over 400 metres before it was boxed. Outside. In the rain, for half the year. Every crate got handled six times.

The funny thing is, nobody had really noticed. It had just become “how we do it here.”

What to do about it. Draw a spaghetti diagram. Honestly, it’s that simple. Take a plan of your site, pick one product, and draw a line for every move it makes. The tangle tells you everything. You won’t always be able to shuffle buildings around, but you can often move a packing bench, put two linked processes side by side, or finally get rid of that “temporary” storage area halfway across the factory that’s been there since 2019.

5. Motion

Motion is the wasted movement of people. Walking, reaching, bending, searching. It’s tiny in any single moment, which is exactly why it slips past. And it costs you in other ways too: sore backs, tired operators, and more mistakes late in the shift.

Field example. An electronics assembler shares a toolbox with two colleagues at the end of a long bench. When we tallied it over a morning, she was walking to it around sixty times a shift. Call it twenty seconds a trip. That’s twenty minutes a day, per person, just fetching things. Across three people and a working year, you’re well past 200 hours. That’s roughly six weeks of somebody’s time. For a toolbox.

What to do about it. This is where 5S earns its keep: Sort, Set in order, Shine, Standardise, Sustain. Don’t let the name put you off. In practice it just means everyone has what they need, where they need it, and nothing they don’t. Shadow boards, point of use storage, parts presented at a sensible height. I’ve seen a £60 set of duplicate screwdrivers pay for itself inside a fortnight. Not glamorous. Works, though.

The wastes built into the work: defects and extra processing

These two tend to feel like “just part of the job.” Which is precisely why they’re so expensive.

6. Defects

A defect is anything that has to be scrapped, reworked, sorted, checked again or sent back. The obvious cost is the material. The real cost is everything wrapped around it.

The American Society for Quality reckons quality related costs run at 15% to 20% of sales revenue for many manufacturers, and as high as 40% at the worst performers. Maybe you read that and think, “not us, surely.” Maybe you’re right. But the same organisation found that only 31% of firms feel they fully understand what poor quality costs them. Most of it hides in labour, overtime and goodwill, not in a neat column marked “scrap.”

Field example. A joinery firm making bespoke staircases had a habit of fixing problems at the fitting stage. A tread slightly out, a baluster hole drilled off centre, and the fitter would just sort it on site. No scrap recorded, so no problem. Except when they finally added it up, the fitters were spending roughly a day a week on rework, plus extra van trips, plus the odd unhappy customer who noticed. It was costing them more than their whole marketing budget. Nobody had ever written it down as a defect, so in a strange way it didn’t exist.

What to do about it. Start counting. Every reject, every bit of rework, every return, logged with a reason. A whiteboard by the door will do. After a month, sort the reasons. You’ll almost always find a handful of causes behind most of the trouble. Then ask “why?” five times about the biggest one, and fix the cause rather than the symptom. Mistake proofing (a simple jig, a locating pin, a go/no go gauge) often costs pennies compared with the problem it solves.

7. Extra processing

Extra processing is doing more work than the customer actually values. Tighter tolerances than the drawing asks for. A finish on a face nobody will ever see. Paperwork that gets filled in, filed and never read again. It’s the sneakiest waste, I think, because it usually comes from good intentions. People want to do a proper job, and that’s a good thing. Mostly.

Field example. A precision engineering firm was hand deburring and polishing an internal face on a bracket. About six minutes a part. When someone finally rang the customer, it turned out that face sat against a rubber mount and was never seen again. Six minutes, across a few thousand parts a year, for nothing at all. Same story with inspection: one critical dimension was being measured by the operator, again by QC, and again at dispatch. Three checks. One good one would’ve done.

What to do about it. Go back to the drawing, literally, and back to the customer. Ask what really matters to them. Then look at each step and ask, “if we stopped doing this tomorrow, would anyone notice?” Be a bit careful, though. Some extra steps exist for a perfectly good reason that somebody forgot to write down. So check before you cut. But do check.

The waste nobody counts: unused talent

8. Non utilised talent

This is the eighth waste, the one that got added later. And if I’m honest, it’s the one I’d put first.

You already pay for the knowledge in your building. Every operator, setter, storeman and driver knows things about your process that you don’t. Things that never make it onto a drawing or into the ERP system. When that knowledge goes unused, it’s waste, just as surely as a skip full of scrap. Arguably more so, because you can’t easily buy it back.

And right now you really can’t. UK manufacturing is short of skilled people, wages keep rising, and around 60% of manufacturers say skills are the main thing holding back their move into automation. So the talent you’ve already got on the payroll is, quite literally, your scarcest resource.

Field example. A setter at a pressings company had worked out, entirely on his own, a way to cut a changeover from about ninety minutes to under forty. Staging the next tool on a trolley beforehand, swapping a few bolts for quick release clamps, that sort of thing. He’d been doing it on his own shifts for over a year. Nobody else knew, because nobody had ever asked him. When the owner finally found out, she said something I’ve heard a few times now: “Why didn’t he just tell us?” I think the honest answer is that he didn’t think anyone wanted to know.

Remember the shop earlier, running 200 brackets to save a changeover? Shorter changeovers make that temptation disappear. The wastes connect like that, which is sort of the point.

What to do about it. Ask. Properly, and regularly. A ten minute huddle at the start of the shift with one question: “what got in your way yesterday?” Write the answers on a board. Fix one small thing every week and tell people you did it. That last bit matters more than you’d think. Ideas dry up fast when they vanish into a suggestion box nobody empties.

Where to start: your first waste walk

So, eight wastes. You might be feeling slightly overwhelmed right now, or maybe a bit defensive. Both are normal. No factory is free of waste. Toyota still finds plenty in theirs after seventy years of looking.

The trick is not to try to fix everything at once. Start with a waste walk instead. Lean folk call it “going to the gemba,” which just means going to the place where the work actually happens. Here’s a version that fits into a busy week:

1. Pick one area. One cell, one line, one product. Not the whole site.
2. Give it one hour. Take a clipboard, a phone for photos and, ideally, the person who works there every day.
3. Stand still and watch. Resist the urge to fix things on the spot. Just look, and keep asking, “does this step add value the customer would pay for?”
4. Use DOWNTIME as your checklist. Go through all eight letters and note what you see under each one.
5. Put a rough cost on the top three. Minutes, metres, pounds. It doesn’t need to be precise. It needs to be honest.
6. Fix one thing within a week. Then walk the same area again a month later and see what’s changed.

One more thing, and it’s a bit of a soapbox moment, so bear with me. Lots of UK firms are spending serious money on digital tools at the moment. The Kaizen Institute points out that 76% of UK manufacturers are investing in digital, AI and automation, yet our productivity still trails the G7 average by roughly 10%. I’m not against technology. Not at all. But if you automate a process full of waste, you just get the same waste, faster, with a nicer dashboard. Fix the basics first. Then buy the kit.

It’s worth knowing, too, that the government’s DRIVE35 scale up fund now lists lean manufacturing as a named technology track alongside digital transformation. That tells you which way the thinking’s heading.

Bringing it together

Let’s step back for a second. The eight wastes aren’t exotic. Overproduction, inventory and waiting hide in your schedule. Transportation and motion are busy moving around your floor. Defects and extra processing are baked into the work itself. And unused talent is sitting in your canteen every morning with a mug of tea, waiting to be asked.

None of this needs a consultant, a software licence or a black belt to spot. It needs you to look at your own factory as if you’d never seen it before. That’s harder than it sounds, I’ll admit. When you’ve walked past the same rack of parts for three years, it stops looking like waste and starts looking like furniture.

Here’s why I think it matters so much right now. You can’t make energy cheaper. You can’t stop employment costs going up. You can’t make customers pay faster or order more. But every hour of waiting you remove, every pallet of stock you don’t need, every rework job you prevent, drops straight through to your bottom line. It’s margin you win back without selling a single extra part. In a year when Make UK is forecasting barely any growth for the sector, that’s not a small thing.

So don’t try to tackle all eight this month. Pick the one that made you wince a little while you were reading. The example that sounded a bit too familiar. Walk that area this week, put a rough number on it, and fix one thing.

Then do it again next month.

That’s it, really. Lean isn’t a project with a finish line. It’s a habit. And the factories that build that habit, quietly and a bit at a time, tend to be the ones still standing (and still growing) when the next cost squeeze comes round. Which, let’s be honest, it will.

If one or two of these wastes felt a bit too close to home while you were reading, that’s honestly a good sign. It means you can already see them. The harder part is building the habit across your whole team, so it isn’t just you spotting waste on the odd afternoon when you’ve got a spare hour. That’s exactly what our Lean Training is for. It’s practical, shop floor training built for UK small and medium manufacturers, not a slide deck about Toyota. Your team learns to spot the eight wastes, run their own waste walks and fix problems at the source, using your products and your processes as the examples. You can find out more and book a place on our Lean Training.