Cancellation of Sprint

> What does the `the work done on them depreciates quickly and must be frequently re-estimated` mean?

Remember that the Definition of Done applies to the increment and not to a Product Backlog Item. The PBI's that were initially planned into a Sprint may or may not be completed by the end of the Sprint, even though the increment meets the DoD.

This means that partially implemented PBI's can be part of a "Done" increment. There will be less work remaining in order to complete those items. However, the work that has been completed so far for a PBI may not be usable until *all* of the work for that PBI is complete. During that delay, the value of the implemented work will depreciate because it is not being put to use and may no longer reflect the latest understanding of scope. The chances of rework being needed will therefore increase, and it will become harder to implement the work that is believed to remain. Estimates must be updated accordingly.

If partially implemented PBI's can be part of a "Done" increment which as i understand is a contributor to the"Done" increment then why we say 'the work that has been completed so far for a PBI may not be usable' in the end we always go for an increment thats usable right ?

An increment must be useful and of release quality. Any undone work which is invested into the increment must not compromise that usability or quality. Incomplete features may be toggled off for example.

Partially completed work represents an unrealized investment which depreciates in value. As such is a potential source of rework and waste, although it can also improve flow across Sprint boundaries.

Ok so the partially implemented PBI's is something in which work was invested but at then end it was not needed to achieve the current sprint goal.

Correct. Some of the planned work, for example, may add value to the Sprint Goal but might not be essential to achieving it. Also, if the Goal is achieved early, other unrelated work might then be actioned.

Thank you Ian !