The Incremental Commitment Spiral Model (ICSM) extends the scope of the original spiral model for software development to cover the definition, development, and evolution of cyber-physical-human systems. It has been successfully applied to systems ranging from small e-services applications to complex cyber-physical-human systems of systems. It is not a one-size-fits-all process model, but uses four essential principles to determine whether, where, and when to use candidate common-case process elements (reuse-based, prototype-based, agile, architected agile, plan-driven, product-line, systems of systems, legacy-based, etc.). The four essential principles are (1) Stakeholder value-based system evolution; (2) Incremental commitment and accountability; (3) Concurrent multi-discipline engineering; and (4) Evidence and risk-based decisions. This presentation covers the four essential principles and their rationale; spiral, phased, concurrency, and process-element-decision process views; associated tools such as an Electronic Process Guide and the Winbook stakeholder win-win requirements negotiation system; and examples of successful ICSM use and pitfalls to avoid. (Based on a book co-authored by Barry Boehm, Jo Ann Lane, Supannika Koolmanojwong, and Richard Turner.)
Dr. Barry Boehm is the TRW Professor in the USC Computer Sciences and Industrial and Systems Engineering Departments. He is also the Chief Scientist of the DoD-Stevens-USC Systems Engineering Research Center, and the founding Director of the USC Center for Systems and Software Engineering. He was director of DARPA-ISTO 1989-92, at TRW 1973-89, at Rand Corporation 1959-73, and at General Dynamics 1955-59. His contributions include the COCOMO family of cost models and the Spiral family of process models. He is a Fellow of the primary professional societies in computing (ACM), aerospace (AIAA), electronics (IEEE), and systems engineering (INCOSE), and a member of the U.S. National Academy of Engineering.
