Dear JG Dobbs,
I think it is a good idea. I was using an Excel sheet as my database, and it is good for small companies. With Excel, we can generate any type of reports, consolidate all the data using a pivot table, filter to get required data, mail merge, etc. Sometimes, I feel this is better than any HRIS. However, later I realized that HRIS is better because it has only one database, and the same gets updated. In the case of Excel, all files won't be updated in the same way, and there would be a multiplicity of sheets or files which we may use for different purposes. To update all would be difficult work (if there are more than one HR person in the department). But with HRIS, we will have a reliable database from which we can import data into Excel and generate any type of reports at any point in time.
So, even though I love to work in Excel, the scope of its usage is limited as it is difficult to have only one file for all your applications.