Spreadsheets are a useful starting point
They are flexible, familiar and effective for exploration. The difficulty starts when a spreadsheet becomes a shared operational system without clear access control, ownership or validation.
Notice the work around the file
Watch for duplicate versions, formulas only one person understands, emailed attachments and hours spent combining updates. The issue is often the surrounding process, rather than the spreadsheet itself.
Improve the process before replacing the tool
Clarify the data structure, who can make changes, what needs approval and which reports people actually use. This makes the current process more dependable and gives any future application a better foundation.
Migrate in manageable steps
Choose one workflow, clean the relevant data and test it with a small group. Preserve access to historical information and make the transition clear to the people doing the work.