The rowing boat: why buffers hide problems

Picture someone in a small rowing boat on open water. Beneath the surface, the seabed is a mess of rocks: jagged, damaging, entirely invisible from above. The water between the hull and those rocks is deep enough that the rower crosses the bay without a thought.

The water is your buffers. Stock levels. Spare capacity. Extra lead time. The workaround somebody built. Redundancy of every kind. And as long as the water is deep, everything looks fine.

That image was shown to me early in my career and it has stayed with me ever since, because it explains something about organizations that’s otherwise very hard to say out loud: the things that make an operation feel safe are frequently the same things preventing it from getting better.

Every buffer has an origin story

Here’s how the water gets deep.

At some point, somebody ran out of something. An experiment was delayed, or a customer order was missed, or a manager asked an uncomfortable question in a meeting. It felt like their fault, whether or not it was.

So they made sure it would never happen again. They doubled what they held. Problem solved.

Except it wasn’t solved. It was covered. And covering it created a set of new costs that nobody added up, because they landed in different places on different people’s budgets: more cash tied up in stock, more expiry write-off, more material scrapped when a project changed direction, more handling, more storage, more racking, more counting. The buffer that was supposed to protect the operation quietly became one of its larger sources of waste.

And the rock, the thing that actually caused the stockout, is still down there. Maybe it was an unreliable supplier lead time. Maybe nobody could see what was already in stock. Maybe the reorder process depended on one person noticing something. Whatever it was, the response was to add water rather than remove the rock.

Keep asking why

The hardest part is resisting the obvious answer. When something runs out, the reflex is to hold more of it. Sometimes that’s right. Usually it’s the least imaginative option available.

So keep asking why until you reach something that’s actually a cause.

• Why did we run out? Because nobody reordered in time.
• Why did nobody reorder in time? Because nobody knew we were low.
• Why did nobody know? Because stock levels live in a spreadsheet that’s updated when someone remembers.
• Why is it updated manually? Because consumption isn’t recorded anywhere at the point of use.
• Why is consumption not recorded? Because we never designed it to be.

And once you have that, the buffer can come down and stay down.

Then brainstorm properly, because there’s usually more than one route. You could shorten the lead time. You could qualify a second source. You could standardize on an item that several teams share instead of four near-identical variants. You could automate replenishment. You could simply stop holding an item that no longer earns its place. There might be five viable options, and increasing stock is only one of them, and rarely the best.

How this maps to PURE

The rowing boat is really a picture of the whole methodology.

Purpose asks why this inventory exists at all, and what the process it supports is actually for. Understand asks what’s really happening and why, which is where the rocks get located. Reimagine asks what this would look like if we designed it today, knowing what we now know. Engineer builds the answer and embeds it.

What the image taught me, and what I’ve found to be true in every operation I’ve worked in since, is that comfort and improvement are often in direct tension. The buffer feels like prudence. Sometimes it genuinely is. But a great deal of the time it’s an unexamined decision somebody made under pressure years ago, which has been quietly costing money ever since, and which nobody has revisited because nothing has gone wrong.

Nothing going wrong isn’t the same as everything being right. It might just mean the water is still deep enough.