Scrum prescribes no forecasting technique. It names burn-downs, burn-ups and
cumulative flow as practices that exist and have proven useful, and states
plainly that they do not replace empiricism.
Forecast and commitment are different things
The Sprint Backlog contains the Sprint Goal, the selected Product Backlog items,
and a plan for delivering them. The Sprint Goal is the commitment. The item list
is a forecast, so as more is learned, scope may be clarified and renegotiated with
the Product Owner, provided the Sprint Goal is not put at risk.
This distinction accounts for a large share of the scenario questions in this
domain. A stakeholder treating a projection as a promise is the usual setup.
Projections come from observation
Any forecast is a projection from what has actually been observed, and it changes
as observation continues. That is what makes it empirical rather than a plan
defended against reality.
Releasing
An Increment may be delivered to stakeholders before the Sprint ends, and
multiple Increments may exist within one Sprint. Release timing is a product
decision rather than a framework rule; the constraint is the Definition of Done.
Common misconceptions
“Velocity is a Scrum measure the team must report.”
Scrum does not define velocity. Burn-downs, burn-ups and cumulative flow are named as practices that exist, not as requirements.
“A forecast of what will be delivered by a date is a commitment.”
The commitment for a Sprint is the Sprint Goal. Selected Product Backlog items are a forecast, and the Developers may renegotiate scope with the Product Owner as more is learned.
“Release planning is a Scrum event.”
Scrum defines five events and release planning is not among them. An Increment may be released whenever it meets the Definition of Done.
4 questions test this concept
A stakeholder asks the product owner to confirm that the eleven items in the current release will all be delivered by 14 November. What is the accurate response, in the framework's terms?
AConfirm it, since the team estimated the work and estimates should be honoured.
BDecline to give any date, because Scrum does not do forecasting.
CAdd contingency items to the release so the date can be met whatever happens.
DExplain that a set of items and a date is a forecast projected from what has been observed so far, that it will change as observation continues, and describe what the forecast currently shows along with what would change it.