Accession Number:



Modeling the Effects of Software-Related Decisions on Early System Cost Estimates: Experience Report from the Software Attributes Trade-off Tool (SWATT) Project

Descriptive Note:

[Technical Report, Special Report]

Corporate Author:

Carnegie Mellon University Software Engineering Institute

Report Date:


Pagination or Media Count:



Although todays major systems rely heavily on software-enabled capabilities, many defense programs look first at the physical items to be developed, assuming the contractors for those items will provide all needed software for the capability. But software by its nature spans physical items. As a result, software engineering considerations are not addressed in early system trades. Software is unduly affected by hardware-first early decisions partly because the main way information is communicated today, within and external to a military system, is through software. Software is required to knit together the information about programmatic decisions made by different contractors, which tend to be optimized to their physical components. This may make the software design unable to be efficient and easy to modify in fact, constraints may prevent the software from meeting appropriate quality goals, as quality attributes are enabled by the software architecture. The resulting design may have significantly worse software complexity, quality, and life-cycle cost than another design could have. Thus, uncertainty, risk, and cost overruns are practically designed-in on such programs.


Subject Categories:

  • Economics and Cost Analysis
  • Computer Programming and Software

Distribution Statement:

[A, Approved For Public Release]