Software Cost Estimation in the Incremental Commitment Model

Complex, software intensive systems — especially those with multiple software component developers — and Directed System of Systems (DSOS) or Acknowledged Systems of Systems (ASOS) need approaches to control the development and estimate the software development costs and schedules. This paper will introduce a next-generation synthesis of the spiral model and other leading process models into the Incremental Commitment Model (ICM). The ICM emphasizes architecting systems (or DSOSs) to encapsulate subsystems (or systems) undergoing the most rapid change, and having agile systems engineers handle longer-range change traffic to rebaseline the plans for future increments. Systems engineers do this, while largely plan-driven teams develop and continuously verify and validate (V&V) the current increment, as is usually required for safe or secure software. Our approach for estimating software development cost of systems is the Constructive Incremental Commitment Cost Model (COINCOMO) and its tool, which currently implements together in one tool the Constructive Cost Model (COCOMO II), and the Constructive Phased Schedule and Effort Model (COPSEMO).