Set made up of interdependent elements which, as a whole, presents its own particular identity and behaviors
Introduction to the notion
Source: Enterprise Transformation Manifesto; paragraph 2.2a.
We will not discuss this operative notion here. We refer you back to the rich literature on this subject.
Let us quote Jean-Louis LEMOIGNE to whom we owe conclusive advances, notably in his “Théorie du Système général” (General System Theory) (1977). Rather than giving a definition of the term “system” below, he gives a summary of the notions that are linked to it and that characterize the systemic approach:
“Something identifiable which, in some other thing (its environment), for something (like a project or a purpose), does something (in the way it functions when in operation), through something in the stable form of its structure, which transforms itself over time (through change).”
It is important to remember the subjective and constructivist value of this notion, well summarized in this other famous quotation by Henri POINCARE: “The system only exists in the human mind.”
This brings us back to the modeler’s situation. For the modeler, the system is not an autonomous “being”, given from outside. It always results from a bias, a decision to cut out a more or less coherent part from the substance of reality that we will exert our understanding on. This conviction must penetrate all modelers, so that they can move the line of what is contingent data towards that which becomes a pertinent construct.
For a brief summary of the main points, totally in keeping with our spirit, see the definition of AFSCET for “System”.
The best sign that how we identify and delimit a system is pertinent lies in the appearance of emerging properties that cannot be attributed to anything other than this system.