Complex systems - General presentation

The purpose of this article is to introduce the "Complex systems" section. Two main aspects are covered in this section: the development and control of these systems.

The term "system" refers to a set of interacting elements pursuing a common goal. The elements may themselves be sets of other elements and, in our case, ultimately people or machines. This is why this article often refers to socio-technical systems.

More specifically, this section is concerned with socio-technical systems and the people within them. It is not intended for the study of technical systems, automatic or otherwise, although some of the methods presented can also be applied to purely technical systems such as regulated ventilation or air-conditioning systems.

More generally, this section is not concerned with systems, technical or human, whose study would be independent of that of the other players who interact with these systems in reality. It does not therefore concern, for example, the study of the operation of an isolated refrigerator, or of a much more sophisticated system such as the autopilot system of an aircraft not integrated into its environment.

• So-called artificial socio-technical systems, in the broadest sense of the term, are the focus of this section. The term "artificial" refers to the underlying notion of the project of one or more human beings at the origin of the system. Thus, this section is particularly interested in complex social systems, such as a company, because, even if some of the elements (the people) are entities not created by other people :

  • on the one hand, the social system formed by the group is itself a human creation;

  • on the other hand, this system is in reality always a socio-technical system, i.e. also made up of machines or, more generally, artifacts (tools...).

  The systems studied can be large or small. The elements of the systems under consideration may, for example, be the various departments and human beings within a company (intra-company perspective). They can also be the companies themselves, as well as their various usual partners (State, banks...) in an economic basin or city (inter-company perspective and institutional players more generally).

• Different definitions of notions such as complexity, model... are given from one article to another by the authors. This only goes to illustrate the plurality of viewpoints that exist on such a vast and not yet sufficiently well-defined theme. But we shouldn't be disconcerted. A number of examples show us that this plurality of viewpoints is often very...