When to Stop? When to deliver?

I was having lunch break with a group of my best staff and collegues; all of a sudden I was struck with the fact that "almost" all of us have the same problem!

As important as it is/was with us, I presume that numerous professionals are having same if not more urgency to find an honest answer to the following questions:

1. When can we stop the "research" process and start the delivery?

2. How can we be sure that our "research" is meeting "our own" expectation?

Especially most of us are prone into "read more, investigate more, and learn more!"
In other words "Knowledge Savvy Pros."!

Thanks

olaimi@infonovation.com