In general, Agile methods are used to help deal with a few of the more common problems with design-first methods (waterfall). In particular, customers are notorious for frequently changing their requirements. This can often render your careful design completely useless or at least badly flawed, assuming you’re using Waterfall or a similar development methodology. If you were using Agile, you might find that this causes a lesser disruption because you don’t need to throw out your design, just your first attempt at the changed feature.

Most agile methods also have a heavy focus on teamwork and fulfilling your obligations to the rest of the team.
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