(1) An adaptive(Ackoff 1971)
(2) Attributes of(INCOSE 1998)
(3) The ability of a system to acclimate physically and functionally to a new operating environment with a minimal degree of degradation to(Wasson 2006)
(4) the ability of the system to become suitable for a new use or purpose and to what range or sources of variation. According to Jackson (2016) adaptability is an attribute of a resilient system.
(1) Ackoff, R.L. 1971. "Towards a System of Systems Concepts." Management Science 11: 11.
(2) INCOSE. 1998. INCOSE SE Terms Glossary. In: INCOSE Concepts and Terms, Working Group (ed.). Seattle, WA, USA: International Council on Systems Engineering.
(3) Wasson, Charles S. 2006. System Analysis, Design, and Development. Edited by A. P. Sage, Wiley Series in Systems Engineering and Management. Hoboken, NJ, USA: John Wiley & Sons.
(4) Jackson, Scott. 2016. "Evaluation of resilience principles for engineered systems." PhD Research, Engineering, University of South Australia.
(1) A system science definition, which applies to any level of system
(2) The term in a software context where it is frequently used, the same idea could apply to human systems. The 1998 INCOSE SE Terms Glossary is an authoritative source.
(3) A more general definition, which applies to complex engineered systems. The book by Wasson is a standard systems engineering textbook.
SEBoK v. 2.0, released 1 June 2019