We just wrapped up our organizations first Scrum project using 2 week iterations. Of course it was a proof of concept project and only had 3 sprints, but it gave us some idea of the possibilities. At the final retrospective feelings were mixed on the team:
- Kept everyone focused.
- We got a lot done in each of the two week iterations.
- From a testing perspective if anything slipped they really got slammed at the end.
- You really needed well thought out requirements before starting on each Sprint to make the Sprint goal.
Overall the takeaway from the team was that two week Sprints could work well for a short project or one with straightforward requirements or a really experienced team. For most larger projects they would feel more comfortable with 30 day Sprints.
Only a single data point for us at this point, but luckily we are starting to acquire a lot more experienced teams being about 1.5 years into a Scrum rollout.