What we typically do today.
This post is about what can be gained from making one simple change in your Resource Custom Field configuration. Many companies have an FTE Yes/No type resource custom field to distinquish between employees and contractors. This has been the approach for many years, as I see this many times in Project 2007/2010/2013 implementations.
A better approach.
I suggest using a Resource Company custom field instead. You would create a lookup table, Resource Companies, where you include the name of your company and the company names of all of your contractors. You then attach this lookup table to the new Resource Company custom field. Lastly, update the value for all resources, where FTEs are set to your company name and contractors are set to their individual company name.
So why do this?
This simple change creates richer data for reporting. For example, your vendor management team is in the process of renegotiating a contract with a specific vendor. That vendor is supplying a number of contractors across many projects. If you use this approach, the ability to extract how much work this vendor is doing and which projects are they working on is as easy as setting a simple filter.
For employees, you may even consider making the lookup value hierarchical, so that you can enable your company name.your division name reporting.
Are you using this approach today? If so, please share your experiences in the comments.