Those interests which pertain to the system development, its operation or any other
aspects that are critical or otherwise important to one or more stakeholders.
Concerns can be logical or physiscal concepts, but they may also include system
considerations such as performance, reliability, security, distribution, and
evolvability. [IEEE Std 1471-2000]
(From aosd.net) A concern is an area of interest or focus in a system. Concerns are
the primary criteria for decomposing software into smaller, more manageable and
comprehensible parts that have meaning to a software engineer (see separation of
concerns). Examples of concerns include requirements, use cases, features, data
structures, quality-of-service issues, variants, intellectual property boundaries,
collaborations, patterns and contracts. There are many formulations used to capture
concerns as well-identified separate units, aspects are one such mechanism, that
are tuned to capturing crosscutting concerns.