PWPM Wiki
Methodology

Agile vs Waterfall

The defining choice in delivery approach: iterate and adapt, or plan up front and execute in sequence.

AgileWaterfall
ApproachIterative, incrementalSequential, phase-gated
RequirementsEvolve throughoutFixed up front
DeliveryFrequent, small incrementsOne delivery at the end
ChangeExpected and cheapDiscouraged and costly
Best forUncertain, fast-changing workStable, well-defined work
VisibilityContinuous via working productVia documents and phase gates

The verdict

Choose Agile when requirements are uncertain and feedback would change what you build; choose Waterfall when scope is stable and predictability is paramount. Many teams land on a hybrid.

Learn more

Read the full pages on Agile and Waterfall.