What I see at most organizations I work with today is an abundance of readily available information on their current suppliers and processes that can tell them how they are performing which only needs to be baselined and compared to market benchmarks. This will help you identify the best and weakest suppliers who you can work with to improve or remove from the program. It also identifies the top performers. And this can be done fast relative to an RF process.
If you are going to do an RF ‘something’ within the contingent workforce category I would save it for evergreen needs in new geographies or skill demands where your current vendors cannot provide the right level of coverage. Let information and good vendor management drive continuous improvement and cost savings.