The Overhead of Iterating
Costs are associated with each iteration. For example, each iteration must be fully regression tested. If this is costly (usually in terms of time), the team may prefer longer, four-week iterations. Naturally, one of the goals for your team should be to reduce—or nearly eliminate—the overhead associated with iterating. But especially during a team’s early iterations, this cost can be significant and will influence the decision about the best iteration length.