Why “You Can’t Do This with Excel” Falls Apart Under One Simple Question
By Hiran de Silva
For nearly three decades, I’ve watched the same demo play out. Starting with, 1998 at Softworld in London – a seminar by Adytum (which was bought by Cognos, and Cognos later bought by IBM)/
A presenter from the Excel-replacement industry — whether it’s Workday Adaptive Planning, Anaplan, or Datarails — shows a polished what-if analysis.
Revenue up 5%.
Revenue up 10%.
Cost of sales rises proportionally.
Margins adjust.
Charts glide smoothly.
And then comes the line:
“You can’t do this with Excel.”
That claim collapses instantly when you ask one real business question.
The Question That Breaks the Demo
“Out of your 300 operating units, one factory is already at maximum capacity.
When revenue increases by 10%, where does the extra production come from?”
Silence.
Because the model doesn’t know.
It can’t:
- Detect capacity constraints
- Trigger a step-change in costs
- Model outsourcing, capex, or cross-factory reallocation
- Handle non-linear behaviour beyond an operating range
The demo assumes a perpetual linear world — one where factories never fill up, prices never affect demand asymmetrically, and reality politely conforms to a spreadsheet-shaped narrative.
That isn’t what-if analysis.
That’s animated arithmetic.
The Reveal They Don’t Want to Say Out Loud
When pressed, the answer eventually appears:
“That would require customisation.”
“That’s advanced.”
“Our product is designed for most businesses.”
Which is another way of saying:
If your business doesn’t fit our assumptions, the model stops being a model.
Yet every business:
- Has capacity limits
- Has thresholds
- Has step-changes
- Has non-linear cause-and-effect relationships
Calling those “edge cases” is absurd.
They are the business.
So What Was the Excel Claim Really About?
Let’s be precise.
The claim is not that Excel can’t do this.
Excel can:
- Model thresholds
- Encode step-functions
- Reflect conditional logic
- Represent real cause-and-effect relationships
That’s what financial modelling actually is.
The real claim is this:
“You can’t do this with Excel if you don’t understand the business.”
And that’s not a software limitation.
That’s a skills and accountability problem.
Who Is This Marketing Aimed At?
That’s the uncomfortable question.
Who hears “revenue up 10%” and never asks:
- Can we physically produce it?
- At what marginal cost?
- With what constraint?
- Over what operating range?
If your audience doesn’t think that way, the demo works beautifully.
If they do — the whole story collapses.
Which makes the repeated industry slogan “You can’t do this with Excel” not just wrong, but misleading by design.
The Bottom Line
A professional modeller can represent real-world business nuance in Excel — or any capable tool — because the intelligence lives in the modeler, not the platform.
If a platform cannot express those nuances at all, then it isn’t replacing Excel.
It’s replacing thinking.
And that’s the real con behind the what-if analysis demo.
This article was inspired by Craig Hatmaker.
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