Why Are You Still Running Dave's Spreadsheet? (Dave Left in 2018)

Quick answer

Every business has a legacy spreadsheet built by someone who left years ago. This article explains what it's actually costing you (time, risk, distrust in your numbers) and how to safely map, rebuild, and replace it instead of feeding it forever out of fear.

Every business has a Dave's spreadsheet.

You know the one. It's been running since about 2015. Dave built it. Dave understood it. Dave left in 2018. And the spreadsheet is still here, still being filled in every week, still feeding something that someone, somewhere, apparently needs.

Nobody alive fully understands how it works.

There are tabs you've never clicked. There's a cell with a formula so long it scrolls off the screen. There's a column called "DO NOT DELETE" with no explanation of what happens if you delete it. There's a macro that runs when you open the file and you have genuinely no idea what it does, only that the file is wrong if you don't let it finish.

And every week, someone updates it. Because the one thing everyone agrees on is this: do not stop creating Dave's spreadsheet. Something downstream might break. You don't know what. You don't know how badly. So you keep feeding the machine.

How did we get here?

Honestly, this is normal. It's not a sign anyone did anything stupid.

Dave was solving a real problem, probably a good one, with the tools he had. The spreadsheet worked. It kept working. So it quietly became load-bearing. Other things got built on top of it. People started trusting its numbers. It crept into reports, into meetings, into decisions.

By the time Dave left, it wasn't a spreadsheet any more. It was infrastructure. And nobody decommissions infrastructure they don't understand, especially when it still seems to work.

The problem isn't that the spreadsheet exists. The problem is what it's quietly costing you now.

What Dave's spreadsheet is actually costing you

It feels free. It's already built, nobody's paying for it, it just runs. But it isn't free.

It's a single point of failure with no documentation. One corrupted file, one wrong paste, one person who finally leaves with the knowledge in their head, and you're in trouble with no manual.

Nobody can improve it. You can't change what you don't understand, so you don't. The business moves on and the spreadsheet stays frozen in 2015, slowly drifting further from how you actually work.

You don't fully trust the numbers. Deep down, you suspect some of it might be wrong. But it's been wrong consistently for years, so you've built around it. That's a quietly terrifying way to run reporting.

It's eating time every single week. Someone updates it. Someone reconciles it when it doesn't match. Someone fields the question "is this number right?" and can't quite answer. That's real hours, every week, forever.

The fear of stopping is real and rational. But the cost of continuing is real too. It's just spread thin enough that you've stopped noticing it.

The fear is the actual problem

Here's the thing worth saying plainly: you're not still running Dave's spreadsheet because it's good. You're running it because you're scared of what happens if you stop.

That fear is the real issue, and it's fixable. Not by bravely deleting the file one Friday and hoping, that genuinely might break something. But by doing the boring, methodical thing nobody got around to.

You work out what the spreadsheet actually does. What feeds it, what it feeds, which numbers leave it and where they land. You find out which bits matter and which bits are leftover from a problem that stopped existing in 2017. You rebuild the parts that earn their place into something documented, something more than one person understands, something that won't leave with the next resignation.

Then you can switch off Dave's spreadsheet on purpose, knowing exactly what was depending on it, instead of feeding it forever out of superstition.

You're not the only one

If this is hitting a nerve, take some comfort: nearly every business we look at has a Dave. Sometimes several. Sometimes Dave's spreadsheet feeds Sandra's spreadsheet which feeds the board pack, and the whole chain is held together by habit and nerves.

It's one of the most common things we untangle, and it's rarely as scary underneath as it feels from the outside. Usually the file is doing far less than everyone fears, or far more than anyone realised. Either way, once it's mapped, the fear goes, and you get to make an actual decision instead of just keeping the candle lit.

The short version

Dave's gone. The spreadsheet shouldn't be running your business by force of habit seven years later. You don't need to be brave about it, you need to understand it, replace what matters, and switch off the rest on purpose.

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Untangling legacy spreadsheets nobody understands is one of the most common jobs we do at Digital Adaption, especially for North West manufacturers running on systems and files that quietly became load-bearing. If you've got a Dave's spreadsheet of your own, let's have a look at it together.