olemus
(a) raamnõue
nõue, mis spetsifitseerib
mitte konkreetseid käitumisviise, vaid
kriteeriume süsteemi töö üle otsustamiseks:
- jõudlus
- käituskitsendus
- platvormikitsendus
- täpsus
- muudetavus
- usaldatavus
- turvalisus
- kasutuslikkus
- õiguslik aspekt

http://reqtest.com/requirements-blog/functional-vs-non-functional-requirements/

https://en.wikipedia.org/wiki/Non-functional_requirement

https://winatalent.com/blog/2020/05/what-are-non-functional-requirements-types-and-examples/

https://www.boxuk.com/insight/guide-to-non-functional-requirements-types-and-examples/


(b) = kvaliteediatribuut

(c) kavanduspiirang
ISO/IEC/IEEE 24765:
tarkvaranõue, mis kirjeldab
mitte seda, mida see tarkvara peab tegema,
vaid seda, kuidas ta seda teeb
=
a software requirement that describes not what the software will do but how the software will do it. Syn: design constraints, non-functional requirement
cf. functional requirement
EXAMPLE:software performance requirements, software external interface requirements, software design constraints, and software quality attributes. Nonfunctional requirements are sometimes difficult to test, so they are usually evaluated subjectively

https://projectresources.cdt.ca.gov/wp-content/uploads/sites/50/2019/09/Non-FunctionalRequirementsTemplate.docx