How is waterfall model is different from iterative waterfall model?

Answer 1

This approach carries less risk than a traditional Waterfall approach but is still far more risky and less efficient than a more Agile approaches. The focus is on delivering a sprint of work as opposed to a series of valuable/shippable features. The most commonly occurring issue in this type of scenario (in my experience) is bottle necking. For example, you deliver loads of code a little bit behind schedule (?) and you leave it until the last minute to test everything. One issue takes longer than expected to resolve, you miss your sprint deadline and you deliver nothing. Another common symptom of this type of approach is over-commitment. It's really difficult to estimate the totaleffort associated with a particular User Story/Feature when approaching delivery in this phased way. You're more or less forced to estimate each phase separately (e.g. estimate development separately to testing in this instance) - this doesn't work as the phases are not separate, they're totally intertwined. For example, if you find an issue with the test, you must return to development. The whole team must remain focused on delivering the end goal, not the separate phases.