The Spreadsheet Holding the Operation Together
A spreadsheet can become a critical piece of the operation without ever having been designed for that. It can clearly reveal what the system is missing.
Why It Appears
A critical spreadsheet can emerge without ever being designed as one: the official system didn't answer a question, someone answered it on their own, and the solution kept being used.
It can be a rational solution to a real problem. The risk isn't that it exists — it's that it was never designed to last, and ends up supporting decisions it was never meant to.
How to Spot the Dangerous Ones
Not all of them matter. It's worth reviewing the ones that meet any of these conditions: more than one person uses it, and no one knows who created it; it feeds a recurring decision — pricing, commissions, inventory, closing the books; if it's lost, something stops; it has formulas nobody dares to touch. A spreadsheet with those four traits is infrastructure, not a file.
What It Says About the System
A critical spreadsheet can point to a specific gap: a piece of data the system doesn't store, a cross-reference it doesn't allow, or a report it doesn't generate.
Before replacing the system, it's worth taking inventory of those spreadsheets and reading them as a list of requirements.
They can work as a useful specification, because they reflect needs the official system isn't covering.
What to Do
The point isn't to ban them. It's to decide which ones need to stop being spreadsheets, and in what order.
It's worth prioritizing the ones involved in processes that touch money.