Long description

The diagram shows four labeled ovals in a diamond: establishing requirements at the top, designing alternatives on the left, prototyping on the bottom and evaluating on the right. There is an unlabeled input arrow to establishing requirements. There are bi-directional arrows between establishing requirements and designing alternatives, and between designing alternatives and prototyping. There is an arrow from prototyping to evaluating. There are arrows from evaluating to designing alternatives, to establishing requirements, and to an external label: final product.