Excel Used Like a Calculator Instead of a System
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Designed and Developed by Paul M. Critchlow, © 2026,
“When Spreadsheets Lie – that false confidence in spreadsheets,” released 10 Feb 2026
Excel Used Like a Calculator Instead of a System
In production and operations reporting, I often find Excel being used like a calculator with memory.
Examples include:
manually adding selected cells for totals
colour-coding rows to indicate categories
Re-calculating totals when items move categories
This feels controlled because the person “did the maths themselves.”
In reality, it introduces a serious risk: double-counting, omissions, and silent drift.
When a single value moves between categories, every manual total must be revisited. If one is missed, the system still produces a number — just not a reliable one.
Excel didn’t fail here.
The system design did.
Question to consider:
If one production figure moved categories today, how many totals would need to be manually corrected?
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