What’s the difference between a Sprint, Iteration, and Increment?
Sprint, Iteration, and Increment are time boxes used to ensure aligned cadence and synchronization in agile teams.
Sprint and Iteration
Sprint and iteration are essentially the same things. The standard duration for each is two weeks. However, on rare occasions, the work context may make a one, two, three, or four-week iteration a better choice.
Ideally, the iterations and their durations remain set so that teams know when to expect specific ceremonies and milestones to occur. A Sprint (or iteration) is just long enough to be able to complete (develop and test) stories while short enough to pivot quickly. The ability to pivot quickly is key to agility. The sprint or iteration time box culminates with a system demo of new features in the staging environment, ready for release.
Program Increment
In a scaled agile environment, a Program Increment (PI) is a timebox that is designed to increase synchronization between all teams (and stakeholders) in the program or portfolio. The recommended PI length is five iterations. A typical pattern is four iterations working on committed features and one Innovation & Planning (IP) iteration. A PI is just long enough to deliver a working (built and tested) increment of value in the staging environment, ready for release. The PI Planning event helps teams discuss dependencies and organize their committed work for the Program Increment. The PI culminates in a stakeholder demo of new integrated features in a staging environment.