When a spreadsheet becomes a liability

Spreadsheets are excellent until they are load-bearing. The failure is rarely dramatic; it is a wrong number in a client report, or a week lost because two versions disagreed.

The five signals

• More than one person edits it, and nobody knows which copy is current
• It drives money: pricing, payroll, invoicing or inventory
• There is a person whose job includes 'maintaining the sheet'
• Formulas have been copied so many times that nobody can explain them
• You cannot answer 'who changed this and when' with confidence

What to replace it with

Not always software. Sometimes it is a validated form plus a database view. Sometimes it is a small internal tool with roles and an audit trail. The test is whether the process needs rules, history and multiple users at once.

A safe migration

• Document the real rules, including the exceptions people handle by memory
• Build the smallest tool that enforces those rules
• Run both in parallel for one cycle and compare outputs
• Archive the sheet as read-only so nobody drifts back