Imagine you have a timebox and a commitment, like a lot of people imagine sprints and sprint plans to be. Now imagine you can't do everything that was agreed upon at the beginning of the sprint by the end of the sprint.
What do you do?
Regardless of theory, in practice, a lot of people seem to want to cut quality. This is counterproductive because quality and speed are deeply-related. Cutting quality rarely makes you go faster in the moment and always makes you go slower in the mid- to long-term.
Time-boxes like sprints are, by definition, fixed length. Sustainable software development is fixed-quality. The only thing left to cut is scope.
Cut quality to go slower. Cut scope to go faster.
