Teams new to Scrum face lots of decisions - one key decision for teams to perform efficiently is determining sprint length.
Scrum and Sprint Definitions
Scrum is an Agile framework that gives teams guidelines on how to complete their work. It contains sets of roles, ceremonies, and considerations for how your work is completed.
A sprint is a concept in scrum that represents a time box - a short amount of time the team has committed to complete the work. Sprints can be as long as you want - however, it's most common for sprints to be between 1 and 4 weeks. Teams running scrum need to decide what makes sense for them.
What we often see is that team's first instincts lean toward the extreme: Either 1 week sprints or 4 weeks sprints. While there are arguments for the varying lengths of sprints, here are some common questions that you and your team should consider:
Planned vs. Unplanned Work
If you are a scrum team that has high variability in your work, longer sprints may give you a necessary buffer. If you've got a one week sprint (with 1 of your 5 days already dedicated to ceremonies), even one or two unplanned pieces of work can prevent your team from completing the committed scope.
On the other hand, if the team has unplanned work with a lower level of urgency, shorter sprints give you the opportunity to include the work in your sprint planning within a shorter time period.
Time Dedicated to Scrum ceremonies
How much time per week should be spent doing sprint planning, retrospectives, backlog grooming, and demos? Shorter sprints mean more time is spent in these meetings. If you do not have dedicated roles (scrum master, product owner) this becomes even more essential.
What we see in 1 week sprints is that teams can lose a full day (twenty percent of the sprint!) of each sprint to demos, retros, and planning. The shorter your sprints are, the more often you're having these ceremonies.
Scope and Size of Tasks
Is your work small enough that it can be completed in the sprint length? If you are often not completing work in 1 sprint, a longer sprint may make sense (or you may just need to work on improving properly sizing your tasks).
How often do I want to see and evaluate completed work? Is it acceptable to go 4 weeks without a demonstration of the work that's being done? Do you need to know every week? Sprint length determines how often you'll see sprint demos and complete sprint retrospectives.
Inspection and Adaptation
There's no one-size-fits-all answer to sprint length, and iteration is the key to scrum - so don't worry if your first choice doesn't work for your team. That's what your retrospectives are for, after all!
For more background on how we do agile, read our case study on how Praecipio Consulting takes on agile transformation.