Setting up Lifecycles

I am relative new to PDM Works and recently started with a company using PDM Works but was not using Lifecycles. The person that was administering the vault has left the company. It looks like we could benefit by using Lifecycles but was wondering if there is an issue in trying to set it up while already having many projects checked into the vault

Any comments or experiences would be appreciated.  Thanks

SolidworksWorkgroup Pdm