Protection of formulae : How often have you forgotten to protect the cell contains the formula that took you hours to test and perfect. It takes one instance of honest human error, and that formula is gone.
Today, there are a large number of options to choose from. The downside to upsizing your spreadsheet to a database system is that databases require fairly in-depth knowledge, especially with regard to extracting data in queries, form construction and reporting.
Judging by this fact, the recommended course of action is to hire the services of a specialized company, a firm that will take care of all the details and subtleties of the spreadsheet programming in your place, and provide you with a ready-made or tailor-made spreadsheet solution that outperforms your expectations.
One user at a time : In the instance where there are a number of people required to work on a spreadsheet, they can only access it when no-one else is working on it.