A spreadsheet can be a sensible beginning
It is familiar, flexible and cheap. A few products and weekly movements may need only item, inbound, outbound and balance columns. Excel remains strong for custom analysis and presentation.
The problem appears when the workbook becomes a hand-built transaction system. Sales, receipts, locations and customer balances depend on linked cells that one person understands and everybody must update perfectly.
Signs the file has become the wrong tool
- several files claim to be the latest copy;
- sales are written now and stock is reduced later;
- nobody can find the movement behind a difference;
- staff need different access rights;
- customer accounts live in a separate notebook;
- mobile product lookup takes too long.
These are structural problems rather than a shortage of formulas.
Record events instead of editing the answer
A cell saying 18 cannot explain itself. A history showing 20 followed by a two-unit shop sale can. The same applies to an outstanding account: a sale and receipt explain the current amount better than overwriting it.
Keep Excel as a downstream tool
Run current operations in Salelog and export supported reports for bespoke analysis. Correct the originating record when possible and create a new export. Maintaining both systems as live ledgers creates reconciliation work.