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System Qualities Ontology, Tradespace, and Affordability (SQOTA)

Descriptive Note:

Technical Report

Corporate Author:

Stevens Institute of Technology, Systems Engineering Research Center Hoboken United States

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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 DoDs 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.

Subject Categories:

  • Computer Programming and Software
  • Computer Systems

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