Length of a Sprint and Change in Time boxes of other events

First of all - to understand that, you first need to understand why the maximum recommended duration of a sprint is 4 weeks.

Secondly, when I don't understand something i try find an analogy OR try to relate it with a real life scenario.

Say, Mr. X has a family (wife, a son, a daughter - who needs a child seat) and they want to buy a car. For him the best buy will most likely be a SUV. (4 week sprints - larger duration of ceremonies to accommodate end to end discussions)

Now Ms Y has a family too - but it is just her husband for now. They can buy a regular hatchback or a sedan. (2 week sprints - shorter duration of ceremonies to accommodate end to end discussions)

And finally, we have Mr Z - who doesn't have a family. He is still single. Would you recommend him to buy a truck or a minivan? Probably not - because it is not really required for his personal use. If it is his business - a different story altogether. (shorter sprints - don't need to invest a lot of time than required - and the reason why events are time-boxed)

When we say time-boxed, it means that you can't go above that set time limit, but if you end early - everything's great. And on of the reasons for time-boxing is to keep the discussion focused.

Sorry for the long post. Hope it helps!

Generally, yes the duration of the time box is proportionnal to the max timebox for 1 month.

Eg. For a 3 week sprint it is 6 hours for Sprint planning, (for 2 week sprint, 4h, and so on) and other events except for the daily which has timebox of 15min regardless. But as our colleague said above a timebox is the maximum of time that an event can have.



For your team maybe you could reasonably increase or decrease a little and see the result with inspection and adaptation.

In Sprints shorter than 1 month (or 4 weeks, which is the longest Sprint duration), the Sprint Planning, Sprint Review, and Sprint Retrospective events may be shorter. Although old versions of the Scrum Guide described the timebox for the events as "proportionately shorter", that phrasing is no longer used - it appears that the October 2011 Scrum Guide was the last one to contain this phrase. This wording required shorter events for shorter Sprints. In today's Scrum Guide, the maximum timebox for Sprint Planning is always 8 hours, regardless of how long your Sprint is. Likewise, the maximum timebox for Sprint Review is 4 hours and Sprint Retrospective is 3 hours.

Personally, I believe that "proportionately shorter" is a good rule-of-thumb and something to strive for, as long as the team is completing the objectives of the event. It is better to have a longer event. If it helps your team, there's no reason why you must end a Sprint Planning at 4 hours just because you are using a 2 week Sprint - maybe 5, 6, or even 8 is better for your team to craft a Sprint Goal, select Product Backlog Items, and develop just enough of a plan to begin executing. In the end, focus on the purpose and goals of each event and allocate enough time to achieve those objectives.

Sprint Planning is time-boxed to a maximum of eight hours for a one-month Sprint. For shorter

Sprints, the event is usually shorter. The Scrum Master ensures that the event takes place and

that attendants understand its purpose. The Scrum Master teaches the Scrum Team to keep it

within the time-box.

There is no mention of how many hours you need for this event for shorter sprints. Basically it should be maximum of 8 hrs (>= 8 hrs) for 1 month and for shorter sprints  > 8 hrs. So, entirely up to your product and time you need initiate the Sprint. How much planning you need to start the real work ? Over planning can produce wastage & so can the under planning.

Sprint Planning answers the following:

• What can be delivered in the Increment resulting from the upcoming Sprint?

• How will the work needed to deliver the Increment be achieved?

Depends when you can achieve the above objective from this event.