Final answer:
The common side-effect of the iterative and incremental life-cycle model is that it becomes less flexible.
Step-by-step explanation:
The common side-effect of the iterative and incremental life-cycle model is that it becomes less flexible. In this model, designs are developed, prototyped, and evaluated in an iterative manner. As the design is refined based on testing and evaluation, changes are made to the design and the process is repeated. While this approach allows for improvements in the design, it can also make the life-cycle model less flexible as it becomes more focused on the current iteration.