Applying process programming to the spiral model

The Spiral Model [Boehm,19S6; Belz,19S6] provides a candidate approach to determining the requirements, architecture, and design of a software process. The Spiral Model activity of determining mission objectives and constraints addresses the requirements for the process: the nature of the product required; budget and schedule constraints; organizational and procedural (e.g. contracting) constraints, etc. The Spiral Model "alternatives" activity addresses process architecture and design considerations: the use of prototypes, simulations and competitive concept definition phases; the choice of incremental products, cutover strategies, and integration strategies; the use of design-to-cost, independent V & V contractors, etc. The choice of process architecture is obtained in the Spiral Model by determining which alternative process architecture minimizes the risk of not meeting the system objectives within the system constraints.