Update Autocad drawing based on PDF mark-up and written instruction

I represent a large industrial services company, operating a large number of sites. All technical installations on site are captured in technical drawings (P&ID's, Isometrics, Wiring Diagrams etc). Every time we implement a change in one of our sites, we need to update our drawings to reflect the change. I am running a trial via Freelancer, to see if updating of drawings is something we can run via Freelancer. This trial concerns the updating of one drawing, based on an instruction, the source file and a marked up PDF ofthe source file. Successful Freelancer can possible expect a much larger volume of such works on an ongoing basis.