Startup Idea: Change Log Software for Spreadsheets

Startup idea to develop a software solution that provides a change tracking system for shared excel files or similar documents. The solution will record changes made by users, allowing easy identification of modifications made, reducing time wasted in backtracking errors.

I would like a software soultion that allows users to see when someone has made a change to an excel spreadsheet or something similar. The problem happens when several users are editing a file and 1 thing changes and someone has to go back through and find out exactly what went wrong to find this problem. It can be very time consuming. If there was a way to check a log of changes that took place than this would be easier to back track.