Rolling Wave Scheduling vs. BDUF

Much has been said over the last few years about the advantage of Rolling Wave Scheduling (planning iteratively, typically in 90 day increments) vs. the traditional BDUF (Big Design Up Front) methods.

With Rolling Wave, you plan the whole project from a high level, but only the nearest horizon (usually 90 days) in detail. Then, as the next 90-day horizon approaches, that phase is planned in detail, etc. For many projects, this is quite appropriate (especially in the IT field), as attempting to plan the unknowable in detail is a futile effort. As John Lennon once said, "Life is what happens to you when you're busy making other plans."

Of course, for some projects, and in some fields, BDUF is still effective. The question you must ask when beginning a project is "Is this project enough like others I've done where I can plan out the whole project in detail, or is much of it unknowable this early in the game?" The approach must be tailored to the project in question. There's no "one size fits all" solution.

As with anything of this nature, there's nothing like experience.