Here are some advantages of keeping iteration lengths consistent throughout the project :
* It can serve as a consistent way of measuring the velocity of the team.
* Establishing a consistent delivery pattern becomes more straightforward using it.
* It is inefficient to decide the iteration length at the beginning of each iteration. Test a few lengths, come to a decision, then stick with it until there is a reason to change.
* Having a consistent iteration length, be it one week, three weeks, or somewhere in between, helps teams settle into the pace that works best for them.
