Interrompere uno Sprint-Iterazione e ripianificarlo é di gran lunga piu efficace che proseguire quando é in grave ritardo e quando attivitá non pianificate prendono la precedenze.
Se da un lato lo Sprint-Iterazione "deve" essere atomica, dall'altro é necessario che sia possibile e facile fare un "rollback". Imho le due cose vanno a bracetto.
Sprint Abnormal Termination
Is the premature cancellation of a Scrum Sprint, due to one of several causes:
- Certainty that the Sprint Goal cannot be achieved
- Urgent bug fix or feature development request that cannot wait until the normal completion of the Sprint
- Fundamental and urgent external changes that invalidate the Sprint Goal or the bulk of the functionality
- Failure of the Scrum Process implementation for reasons such as:
- fundamental team conflict
- inability to engage Product Owner to get answers for the team
What you can try to save the Sprint ?
- Innovate/remove impediments - quickly analyze the root cause of the problem (blocked story, resources diverted to emergency, or whatever) and see what ideas the team has to correct the problem. As always, the collective minds of the team are the first and best resource.
- Get Help - can help be found outside the team? If so, apply these resources to accelerate the burn down. (and remember that adding new people to the team will slow down the Sprint)
- Reduce scope - cut lower priority features and re-plan based upon what the team canaccomplish. While the team might not be able to deliver all the stories, it may not be too late to fulfill the objectives of the sprint and still end up in an acceptable state at the end.
How to restart after a Sprint Abnormal Termination?
After Sprint is canceled there is a meeting with the team and the people involved in the Sprint cancellation where the reasons of Sprint cancellation are discussed.
Further a new Sprint begins with a planning meeting where priority are discussed and the new goal for the Sprint is set.