How long does it take to implement a PRM?

As with any platform so core to the primary business function, this is not a trivial activity. Time must be allocated for data normalization and transfer from a variety of sources. Users must be trained. Partners must be enlisted, deployed, and trained. Processes must be adopted. And everything possible needs to be done to communicate to all users how much value they can extract from this new resource so your rate of adoption remains high. Nothing kills a project like poor adoption.