Do you believe that cross functional teams help increase the chances for a successful project? Why?

I believe that having a cross functional teams is essential for enabling success in any project. Having a cross functional teams enables:

1). Specialisation of key tasks to functional owners.

2). Determination of critical path.

3). Output Quality Improvement. 

4). Structured approach and feedback mechanism. 

Not in ll cases . functional team are very related/followed their functional manager & if you can't build great relation ship with them or their manager in favor of your project then you will not get much from them. I have to share with them the benfits of working in such project for the company & for them selves.