The 5 most common margin leaks in manufacturing — and how a Virtual CFO finds them in week one

Manufacturing businesses have a particular kind of margin problem. It's not dramatic — no single event you can point to. It's a slow leak across five or six places simultaneously, each one small enough to explain away in isolation, but collectively they're the reason your net margin sits at 6% when it should be 11%.

When I come into a manufacturing business for the first time, I'm not waiting for month three to form an opinion. In week one, I'm looking at five specific places. Here's what they are and what I find.

1. Cost of goods sold that hasn't been rebuilt since the last price cycle

Your cost of goods sold should be rebuilt every time a major input price moves. Raw materials, freight, packaging, energy — all of these have moved materially in the last 24 months. Most businesses I see are still running cost structures that were set in 2022. If your selling prices have been adjusted but your COGS hasn't been properly restated, you don't actually know what your margin is. You know what it was.

The fix is unglamorous: sit down with the production team and rebuild the standard cost from scratch for your top 10 SKUs by revenue. Two days of work that typically changes the margin picture by 2 to 4 percentage points — in either direction.

2. Labour absorption that doesn't reflect reality

Standard costing allocates labour to products based on estimated hours. The problem is that the estimate was made when the line was running at a different efficiency level. Overtime, shift changes, and rework all eat into the planned hours without showing up in a way that's easy to see. The product looks profitable on paper; the actual cost to make it is 15% higher.

I look at actual hours versus standard hours by product line, and then I look at where the variance is being parked in the accounts. If it's sitting in a 'production variance' account that nobody reviews, you've found the leak.

3. Inventory that's older than it should be

Working capital tied up in slow-moving or obsolete inventory is a margin killer twice over. First, you've paid for the material and it's not turning into revenue. Second, when it eventually moves — or gets written off — the hit lands in a single period and distorts the picture for that month.

A basic age analysis of inventory, segmented by category, tells you exactly where the capital is stuck. In most mid-market manufacturing businesses I've worked with, 20% of SKUs account for less than 2% of throughput. Those SKUs are candidates for discontinuation, price adjustment, or a clearance run. Freeing that working capital typically improves cash conversion by 15 to 20 days.

4. Overhead allocations that no one has questioned in years

Fixed overhead gets allocated to products via a rate that was set at some point in the past based on some assumption about volume. If actual volume is consistently different from that assumption, every product in your range is being costed incorrectly. Low-volume products look artificially cheap (because they're absorbing less overhead than they should). High-volume products subsidise them.

This is where product-level profitability analysis gets interesting. When you rebuild the overhead allocation with current volume assumptions, the ranking of your most and least profitable products often changes completely. I've seen businesses discover that their flagship product — the one they lead every sales conversation with — was their third-least profitable line.

5. Pricing that was set on cost-plus and never revisited

Cost-plus pricing is logical when you set it. Add up your costs, add your margin, that's your price. The problem is that the market doesn't care about your costs — it prices on value and competitive positioning. And when your cost base moves but your price stays fixed because 'that's what the market expects', your margin takes the hit.

The discipline here is separating pricing decisions from cost-recovery decisions. You price to win the right clients at a sustainable margin. You manage costs to protect that margin. When the two conversations are merged, pricing becomes reactive and defensive — and margin follows.

What the first week actually looks like

In week one I'm reviewing your last 12 months of management accounts, your inventory age analysis, your top 20 SKUs by revenue and margin, and your standard cost cards. I'm looking for the pattern, not the perfect answer. By the end of week one I can tell you where the leaks are and what they're costing you annually. The fix plan comes in week two.

Most manufacturing businesses I work with are leaving between 3% and 6% of gross margin on the table across these five areas. On a R20M revenue business, that's R600K to R1.2M per year. The Virtual CFO engagement costs a fraction of that.

If any of the five leaks above sound familiar, take a seat in the boardroom and tell me which ones. We'll start there.