The question of “what’s the right iteration length” may not be as interesting as any of the questions found here (gum really doesn’t stay in you for 7 years. Who knew?), but it is a common question from organizations moving to agile development. You can certainly get a lot of different opinions on this from a Google search, but since you’re reading this now, I’ll give you mine, based on personal experience.
A number of years ago, one of the projects I was PM on decided to try out Scrum. I had attended some Product Owner training, and our soon-to-be Scrum Master had been on some training as well, but we were very green and decided to approach things with a “let’s see what works best for us” mentality. At the time, we thought the best way for us to get immersed and efficient with Scrum was lots of repetitions. We went with 1-week iterations, thinking that by having a rapid and regular cycle of sprint planning meetings, demo meetings, retrospective meetings, etc. we would learn more quickly the “proper” way of doing development with Scrum.
We certainly did learn a lot during our first 3 or 4 sprints, mainly that having this regular weekly cycle of meetings was just too much overhead, and the actual amount of value produced at the end of each sprint was too little. Next on our list, the 2-week sprint.
The 2-week sprints worked great for us, and we saw the differences from the 1-week sprints almost immediately. We were producing what we thought was a good amount of value from each sprint, but with a better and more balanced level of overhead. We hit our groove and established a good cadence with these 2-week sprints, and from the looks of the burn-down chart, we were becoming a more efficient team with every sprint.
The team definitely was cruising and enjoying the pace, but the holiday season snuck up on us and we thought that it might make sense to make some adjustments to deal with the vacation time various team members would be taking.
After collecting everyone’s vacation schedule, we were able to determine a start and finish date for our “holiday sprint” that would essentially start when everyone was still in the office, and finish when everyone returned from their vacation. Call it either luck or good management, but we had planned a 4-week sprint. I won’t go through all the gory details, but let’s just say that upon reflection, the 4-week iteration just felt wrong.
The initial planning session felt harder to estimate the amount of work we could do. The cadence we developed didn’t show itself, and it really felt like we never gained any momentum during the 4 weeks. Now I’m sure that the whole holiday season thing played a role in this, but it was our least effective iteration ever, and by a lot. We never tried the 4-week iteration again.
The bottom line is that all teams are different and need to go with the iteration length that feels right for them. For us, the 2-week one was best.
For the record, I have always wondered if the 7-year rule for chewing gum was true. Glad to hear it isn’t.