Spreadsheets earned their place. They’re flexible, everyone can use them, and they solved a real problem faster than any system would have. Nobody chose to run a supply chain on them — it accumulated, one workaround at a time, and each individual step was sensible.
The cost is real, though, and it’s almost entirely invisible because it doesn’t appear as a line item anywhere.
Time, First
Count the hours your planners and buyers spend extracting data, reformatting it, reconciling versions, and rebuilding the same analysis every week. In most mid-sized manufacturers this runs to one or two full-time equivalents’ worth of effort — done by your most experienced people, on work that produces nothing except a version of information that already existed elsewhere.
That’s the opportunity cost that matters. Those are the people who should be developing suppliers, resolving constraints, and improving processes.
Errors You Don’t Find
Research on spreadsheet error rates is consistent and uncomfortable: a meaningful proportion of operational spreadsheets contain material errors. A dragged formula that stopped one row short. A hardcoded number where a reference should be. A filter left applied. A copy that diverged from the original months ago.
None of these announce themselves. They produce plausible-looking numbers that are wrong, decisions get made on them, and the consequence shows up later as a shortage or an overbuy that gets attributed to market conditions.
Decisions That Arrive Too Late
A spreadsheet is a snapshot. By the time it’s built, checked, and circulated, the underlying position has moved. Planning on Monday’s data on Thursday means every decision carries three days of drift.
This compounds: because refreshing is laborious, it happens weekly rather than daily, so the drift is larger, so the buffers built to absorb it are larger, so inventory is higher. The spreadsheet’s cost shows up on your balance sheet.
Analysis You Can’t Do
Some calculations are simply out of reach. Multi-echelon inventory optimisation. Constraint-based scheduling across a full order book. Per-item safety stock from measured variability across thousands of SKUs. Scenario comparison across a live network.
So they don’t get done, and the decisions they’d inform get made on rules of thumb instead. The gap between a rule of thumb and an optimised answer is not visible — which is exactly why it persists.
Knowledge Held by One Person
The most serious risk is concentration. Critical planning spreadsheets are usually built and maintained by one person, undocumented, containing logic that exists nowhere else. When they leave, or are ill during a peak, the capability leaves with them. Most manufacturers discover this at the worst possible moment.
What to do about it
You don’t need to eliminate spreadsheets. They remain excellent for one-off analysis and modelling. What should move is anything recurring, anything feeding a repeated decision, and anything only one person understands.
Start by listing your operational spreadsheets, who maintains each, and what decision it drives. The list is usually longer than expected, and it makes the case on its own.
ticktick.ai replaces the recurring analysis while leaving your team free to model ad hoc questions however they prefer.
