As software and applications developers and Managers of the same, I think many of us struggle with the Pros and Cons of the varied development processes available to us. There are many methodologies available and a simple click over to Wikipedia will generate a cascade of more pages than you have time to read.
If you have time for a quick straight forward discussion of two points of view, have a read through Matt Ward's discussion "On the Concept of Process" published by DESIGNM.AG. Matt has written a short discussion that I am sure echoes the experience of many developers and certainly that of myself and many of my colleagues.