Standard Manhours for Isometric Drw

Hi Guys,

Would appreciate your advise on the typical manhours required to prepare an isometric drw. Was told by our consultant that the industry (oil&gas) standard manhour for preparing one isometric drw is about 15-20 hrs.

Fyi, we generate the iso from the electronic 3D model (Integraph PDS 3D software). Let say if we require 1000 iso drws, then the total hours is 20,000. From this we could estimate the manpower required for the job.

Thanks

norzul