I believe this Hentzenwerke book purports to give you guidance on this issue:

http://www.hentzenwerke.com/catalog/sdg3.htm

More specifically, check out the table of contents, chapter 17:

http://www.hentzenwerke.com/catalog/sdg3toc.htm


>Hi all,
>
>I've been asked to project the number of hours required to complete a project.
>
>Is there a method or system that would assist me to project that? I've never done this before.
>
>Any help will be greatlly appriciated!