an entity with a boundary that is not closed. It receives
input s and produces outputs. (
Umpleby )
A
system with
input , an entity that changes its
behavior in response to conditions outside its boundaries. Systems are rarely ever either open or closed but open to some and closed to other influences (
see channel ). Because of their need to combat decay within, food intake makes biological organisms and societies open to matter/ENERGY from their environment. But this property says nothing about openness to information.
adaptation, learning and all manifestations of
intelligence require some openness to
information. Unlike biological organisms,
computers and social institutions exemplify openness to
organization which indicates that structural changes are determined from the outside. Whether or not a system has outputs does not enter the distinction between open and closed systems. Systems without output are non-knowable by an external observer, e.g., black holes in the visible universe (
see ether ). Systems without inputs are not controllable (
see control, closed system ). (
Krippendorff )
