System Qualities Ontology, Tradespace, and Affordability (SQOTA) Phases 1-7
Systems Engineering and Systems Management Transformation
Report Number: SERC-2019-TR-012
Publication Date: 2019-08-23
Project: Tradespace and Affordability
Dr. Barry Boehm
Systems and software qualities (SQs) are also known as non-functional requirements (NFRs). Where functional requirements (FRs) specify what a system should do, the NFRs specify how well the system should do them. Many of them, such as Reliability, Availability, Maintainability, Usability, Affordability, Interoperability, and Adaptability, are often called “ilities,” but not to the exclusion of other SQs such as Security, Safety, Resilience, Robustness, Accuracy, and Speed.
As compared to functional requirements, NFRs have been underemphasized in project management, and serious sources of project shortfalls and overruns. They are often late in being thoroughly reviewed, being preceded by reviews such as the System Functional Requirement Review. They do not have a place in function-oriented management aids such as Work Breakdown Structures and traceability diagrams: the NFRs generally trace to the whole system. Their requirements are often easy to specify and hard to validate: one classic case was a project in which changing one character in the NFR for system response time in seconds from a 1 to a 4 in a 2000-page specification reduced the cost of achieving the system from $100 million to $30 million.
This report begins with a summary of the origin of the SERC project as the result of SERC universities’ participation in two 2012 workshops that addressed the challenges of achieving one such NFR: resilience, in support of one of DoD’s high-priority initiatives on Engineered Resilient Systems (ERS). It turned out that the existing ERS research underway was primarily directed at field testing, supercomputer modeling, and resilient design of physical systems, and that the SERC could best complement this research by addressing the design and development of resilient cyber-physical-human (CPH) systems.
Some of the SERC universities involved in the workshops were performing such research, such as AFIT, Georgia Tech, MIT, NPS, Penn State, USC, U. Virginia, and Wayne State. These universities have been addressing aspects of this research area as a team since 2013, culminating in Phase 7 in August 2019. This final report summarizes their overall achievements, in the alphabetical order above.