Eight ways a spreadsheet feasibility model goes wrong.

The eight risks

1. Hard-coded cells inside formulas. Search for any cell that returns a number that isn't from a referenced input.
2. Hidden tabs. Unhide every tab before circulating the model.
3. Broken named ranges. Check the Name Manager — orphaned ranges are common.
4. Circular references in finance. Especially when interest is calculated on a balance that depends on interest.
5. Out-of-date pricing. Comparable sales over 3 months old.
6. Out-of-date contributions. Statutory schedules update annually.
7. Annual cashflow only. Annual is too coarse for peak debt and IRR.
8. "Final" version that isn't. File naming is not version control.

The structural fix

The reason these errors recur is that a spreadsheet has no structure to prevent them. A structured tool — like Feaso — eliminates the class of error rather than catching individual instances.