appointment scheduling without using MRS in PM orders

Hi ,

We attach workcenters or personal numbers to order operations . If work is more than the availbel capacity in work center order gives warning . In work centers we have people and positions mapped . My client wants before even saving order , he would like to see what is the avilable capacity of each staff (PM -HRMS integration) by inputting position . If gets some persons during the operation dates , he will assign persons to that work center of operations (kind of appointment scheduling) . I am aware this is possible through MRS , where in you input an order , can see load of staff on required dates and drag and drop personal to order , if they are available .

How can we achieve this in PM order .