Length of an Iteration

Factors influencing the iteration length

Earlier, we described a project in which the iterations lasted for six months. This isn’t optimal. Why not? What’s a good length for iterations? Is there an ideal length? Here are some factors that influence the ideal length:

• Short projects or releases: To provide a project with a length of three to six months, optimal feedback, and prioritization intervals, a short to ultrashort length of iterations is best. Choose iterations of one or two weeks. The same goes for long-term projects that are delivered in releases. This is especially common in organizations that develop a product continuously. Each year, several releases of the product are launched, often with fixed release dates. Each release can be considered a short-term project. In addition, organizations that develop mobile or web applications are often aiming for a short time to market. These companies choose ultrashort iterations, implementing changes as fast as Facebook.

• New teams: A team that’s new to Agile often opts for longer iterations. We advise against this. In longer iterations, teams tend to fall back on a mini-waterfall. That is, the team first designs all selected work items, then develops all the work items. Such a team rushes through testing in the last few days of the iteration. The risk is that the team hasn’t fully delivered any work item at the end of the iteration due to the higher complexity of the work items or lower-than-expected velocity. That’s why we advise new teams to work with short iterations and stick to them.