Part 1 of the two-part paper on the hierarchical spiral model introduced its theoretical background, consisting of the sociocybernetic metamodel for information system (IS) and software (SW) design and a three-level model for the IS/SW product. Part 2 describes the hierarchical spiral model for IS and SW development in detail as an integrative framework that includes the evolution dynamics of IS/SW products, defining their operational life-cycles at the three levels of modelling, the main phase dynamics of the IS/SW design process, defining the main phases required for the generation of each new operational life-cycle, learning dynamics, suggesting that each main phase consists of successive subphases that may be repeated during IS/SW design, depending on the learning process, and the nonlinear structure of the main phases intertwining the three levels of modelling in a specific way. © 1990.
