Resouce (Manpower) planning in PS

Hi All

In our R & D projects, mangement wants to track Resources(Personnel,Manpower) means planning, allocation and tracking of Persons involved in a project. As per my knowledge we can use Resource planning in PS but for that integration of HR module with PS is required, but in our company HR module is not implemented.

My question is that am i correct that we can only do manpower or personnel planning and tracking thru PS if HR module is there?. And, if it is possible to do without HR module being implemented then how can we do that?

Please Advice..

Thanks in advance