Standard Costing for Labor

I am trying to get a sense of the number of companies that are costing labor at standard rates (instead of actual rates).  I am especially interested in the instances for US operations.

We feel we should be using standard labor cost in a move to adopt Oracle Project Management and recognize there are instances where actual costs may be required (e.g. Federally Funded projects).  We can design a solution to deal with the two instance but are wondering if it is worth the effort.