Answer:
The critieria is based on what other techniques you might employ. The waterfall method in SDLC (software development life cycle) has been largely discounted in favor of more effective methods, such as the iterative approach.
One of the main problems with the waterfall design is that it does not easily allow for negative feedback at several stages of the project (for example, water flows downhill, not uphill, so feedback into the cycle can be very costly).