This is one way of making the life cycle iterative,
where a phase may be executed several times.
Feedback can also occur across the entire software development life cycle.
There are two lifecycle models which are considered iterative in nature.
The first of these is the incremental model, Ketrell characterizes this
model as having overall requirements phase and initial design phase.
Followed by multiple cycles through the remainder of a lifecycle In this figure
each of the three iterations begins with the detailed design phase.
Although development proceeds in increments,
there is a single requirements phase for the entire project.
The advantage of this process is that there is some semblance for
a product early on, which has a positive effect on team motivation.