"Iterative development plans to rework items. Not because they are of low quality, not because they are defective, not because they are unacceptable, but because we chose to limit the scope of them earlier so that we can get to learn something about them sooner. This is a product development technique. Kanban is mainly a manufacturing technique. Software development resembles manufacturing to a degree of approximately 0.0 so it’s a bit of a puzzle why this manufacturing technique has become quite so popular with software developers. Added to which the software industry has a catastrophically bad track record at adopting management ideas from manufacturing in an appropriate way. We in IT are perennial confused about manufacturing, product development and engineering, three related but very different kinds of activity."