Hi Katherine,
in addition to Hemant, just wanted to add that when you have your employee records with the last access date available, you should look into the sysdate() function and date_diff() function, as well as some of the data conversion functions that are available in Information Steward within the Rule Expression Editor.
Search in the User manual of Information Steward for sysdate(), there are nice starting pointers.
E.g. date_diff($start_date,sysdate(),'D')
And by the way, Rama is right that Information Steward is very often used for profiling and assessing Master Data objects like Customer, Supplier, Material, Employee records, but nevertheless, Information Steward allows profiling and assessing ANY kind of data objects, be it Master data, Transactional data, operational data, ... Customers are using e.g. Information Steward to asses the quality of their APO data or reporting data before they are making decisions based on that data to ensure they do their decisions based on high quality, reliable data..
Niels