Spiral model - Wikipedia
https://en.wikipedia.org/wiki/Spiral_modelThe spiral model is a risk-driven software development process model. Based on the unique risk patterns of a given project, the spiral model guides a team to adopt elements of one or more process models, such as incremental, waterfall, or evolutionary prototyping.
SDLC Spiral Model - W3schools
www.w3schools.in › sdlc-tutorial › spiral-modelThe spiral model is another important SDLC model that came into use when the iteration in product development came into the applied concept. The initial phase of the Spiral model is the early stages of Waterfall Life Cycle that are needed to develop a software product. This model supports risk handling, and the project is delivered in loops.