Image by J.Y. Loke on Shutterstock

Part 2

Iterative Lifecycles

What Lifecycle or Agile Approach Fits Your Context?

Back in Part 1, you learned how stage-gate approaches were as agile as we could use at the time.

Serial Lifecycles

We had one delivery, so our agility was about canceling the project if we couldn’t finish it.

However, some smart people also realized that we had another lever — aside from estimation — to replan the project. We could get feedback on prototypes from the customer. That feedback would allow us to replan.

The Spiral Model

Conny, CC BY-SA 3.0, via Wikimedia Commons

Barry Boehm developed the spiral model. This image shows several ideas:

• We use prototypes to reduce requirements risks.
• We develop test plans early.
• We use prototypes to inform the detailed planning, design, and so on.