Too Little Too Soon. Modeling the Risks of Spiral Development

摘要

The DoD's evolutionary acquisition policy is directed against project risk, but bears inherent risks of its own. The DoD policy for evolutionary acquisition mandates multiple product releases via spiral (i.e., amorphous and unplanned) or incremental (i.e., defined & deferred) development methodologies for all programs. All amorphous spirals eventually become definitive increments. Incremental development entails the deliberate deferral of work to a subsequent phase. Computational organizational modeling using systems dynamics reveals that this methodology introduces more concurrency during development, and more variety in production. The result is earlier delivery of the first increment, but with later and more costly delivery of subsequent increments than if conducted via a single-step methodology.