From spreadsheet to application: when is the moment?

Nearly every construction and real-estate organisation has them: the files the company actually runs on. They started as a helper and grew into systems without an owner, documentation or backup strategy.

Six signals the spreadsheet has reached its limit

1. 1More than two people need to work in it simultaneously.
2. 2Variants exist named final_v7_really.
3. 3Someone enters the same data in another system too.
4. 4Errors surface only at invoicing or handover.
5. 5Only one person dares change the formulas.
6. 6It contains personal or contract data without access control.

Migration in four steps

1. 1Reverse engineering: we document the business rules hidden in the file.
2. 2Redesign: we decide together which rules stay, go or are missing.
3. 3Parallel phase: the application runs alongside the spreadsheet so results can be compared.
4. 4Handover: the spreadsheet is frozen only after results demonstrably match.