Pros and cons of short iterations

November 23, 2006 by Artem

All the agile software development processes are iterative. Iterations are used in order to release complete increments of software within predictable periods of time and get customer or pseudo-customer feedback early. Different processes recommend different iteration lengths. Scrum is very strict in this sense and requires exactly 30 calendar days long iterations. This period of time is considered being a typical amount of time that product owner can allow the team go independently without the external control. eXtreme Programming brings the idea of frequent customer feedback to the extreme level and advocates for shorter iterations down to one week long.

Pros of the short iterations

- Very tight feedback loop. Feedback is gathered early, customer corrections are easier to integrate
- First deliveries are released real soon. Tight feedback loop is always important. The first feedback is even more important, than usually
- Strong focus. One or even two weeks are usually two short amount of time to loose the initial commitments and to start working on something not agreed with the customer

Cons of the short iterations

- High overhead. The shorter the iteration is and the more ceremony the process has, the more time is spent on retrospectives, reporting, re-planning, etc.
- More difficult to get resources on time. The shorter your planning horizon is, the more difficult it is to order the external resources like consultations or prototypes on time
- More chances to miss the big picture while digging in the small details
- Relatively high level of automation is required. Not to loose too much time on procedural overhead, everything that could be automated, should be automated. It is much easier to go for short iterations with the continuous integration and automated releasing in place

What iteration size is right for you?

The agile-style answer would be to try couple of different values and see which is working better in your situation. Start with smaller iterations in the beginning to get the most important first feedback early and then extend if you feel that too much time is spent on transactional issue.

What is the iteration size in your team? Why did you choose this size?

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