The Excel sheet that runs your factory

Every prefab HSB factory has one. You know the sheet. It's on one person's laptop. It has forty tabs. Half of them are colour-coded in a system nobody but the author understands. There are formulas three layers deep that reference other sheets that have been renamed. Macros that haven't been touched in six years because nobody is sure what breaks if they are.

And it runs your factory.

The research says what you already know

A 2008 study by University of Hawaii researchers audited real-world business spreadsheets and found that 88 percent contained at least one material error. The figure has been reproduced in dozens of follow-up studies. Spreadsheets in industrial settings fail at roughly the same rate as spreadsheets in banks.

In a prefab HSB context, a material error in the master BOM sheet doesn't stop at a wrong number on a balance sheet. It propagates: wrong material quantities ordered, wrong cut list, wrong invoice to the client. By the time you catch it, five other sheets have been updated from the bad source.

Why the sheet keeps winning

Most factories built their Excel over a decade. It encodes real operational knowledge: which supplier delivers which SKU, how the factory rounds for waste, which elements take extra time, how night shift affects capacity planning. No off-the-shelf software captures this. So the sheet stays.

The result is a factory that depends on one person's Excel to ship. When that person takes three weeks of vacation, the factory slows down. When they leave, the factory panics.

What replaces a mature Excel

Not a generic ERP module. ERPs were written for companies that look like other companies, not for a prefab timber frame factory with its own rules.

What replaces it is a data layer that captures the logic – the supplier mappings, the waste factors, the element-type exceptions – in a system that is auditable, versioned, and not living on one laptop. A system that eats the BIM data on one end and emits production orders, cut lists, and ERP-ready data on the other end, with the factory's own rules baked in.

The goal is not to remove the factory's intelligence. The goal is to get it out of the spreadsheet and into something that doesn't break when the author is on holiday.

Koto captures your production logic in a layer that doesn't depend on one laptop. If your Excel is doing too much work, we'd like to see what it's doing.