It will take some time to determine the quality of a new hire, but the longer the employee is at the company, the easier it will be to establish. This should take into account not only performance ratings, but also their potential. Over time, you will be able to see a trend in their performance reviews, and determine their overall worth to the organization. This metric can then be linked to the sourcing channels to help determine where the highest quality candidates originated from, as well as the time to hire so recruiters can get a sense of how long it takes to find the right candidate