When is a functional resume advanganteous?

In reality, it is never considered an advantage over a chronological resume. Recruiters want to know when, where, and what you did. Merely stating that you did a certain task will given the idea that you may be hiding something. You are welcome to put terms in the summary that will provide a clear picture of what you did, but those are bulletized, short, and succinct. If I were a recruiter I'd want to know when you worked on this project and for whom. Hope that helps. If you want your resume given a critical resume, simply email it to Howie at hra246@gmail.com. I will point out the "red flags".