The biggest problem encountered when discussing the three concepts systems, innovation, and leadership is that people rarely agree on what the words mean when they are used. To help narrow down the list I will state explicitly that I am using these terms in their general sense and avoiding using them as specific jargon like you would find in a technical medical or computer discussion.
This post is the first in a three-part series. Each instalment will investigate the definition of a word by summarizing the process I went through to generate a useful definition.
The history of the word, as related by the Online Etymology Dictionary, can be traced back to the word 'systema' which is made up of 'syn' (together) + root of 'histanai' (cause to stand); meaning "set of correlated principles, facts, ideas, etc."
The Random House Dictionary has a half dozen (relevant) overlapping definitions of the word. They can be condensed like this: an [ordered/comprehensive/coordinated/formulated/regular] [assemblage/combination/set/body] of [things/parts/members/facts/principles/doctrine/methods/schema] forming a [complex/unitary] [whole/scheme].
The American Heritage Dictionary has fewer overlapping definitions: A [group/organized set] of [interacting/interrelated/interdependent/functionally related/coordinated] [elements/ideas/principles/objects/phenomena] forming a complex [whole/order].
The Merriam-Webster Dictionary has even fewer: A [interacting/interdependent/related] [group/arrangement] of [items/bodies/objects/forces/devices] forming a [unified/harmonious] [whole/network].
If all that could be further condensed down to a single sentence it might look something like this: a system is an integrated group of things which form a whole. However, I think there is an important concept being left out of these definitions.
An important concept to capture is that at any given moment a system is an arbitrary boundary drawn somewhere in a hierarchy of subsystems. A system is simultaneously a system and a subsystem, so defining it in relation to its subsystems makes it a sort of self-referential meta-definition. It's not as simple as nesting dolls. . .
. . .it's more like a fractal.
Therefore, I propose the following definition of 'system': a purposeful choice of scale in an infinitely complex hierarchy of nesting subsystems, the discussion of which involves integrated collections of related things.
For some other discussions of the definition of systems The Univ. of Missouri-St. Louis, the Division on Systemic Change, and the International Society for System Sciences are valuable resources.