Model Based Systems Engineering: Fundamentals and Methods

1

General Systems Theory

1.1. Introduction

What do a nerve cell, the mathematical field of complex numbers and the Rosetta stone have in common? Nothing much, apparently. However, all three are systems, each in its own way. To grasp the unity behind this diversity of appearances, we must resort to general systems theory (GST), a theory that does not concern a specific type of systems in particular, but instead what makes a system a system. In the following, we will refer to GST, developed by Mario A. Bunge, in particular in volume 4 of his Treatise on Basic Philosophy [BUN 79]. We consider that Bunge’s theory develops that of L. von Bertalanffy [BER 69], as well as renews it.

In this chapter, we define a system as a composite object characterized by (1) its composition, (2) its environment and (3) its structure. We will differentiate two types of systems: abstract or concrete depending on whether the objects composing the system are abstract or concrete. We will examine the relationships between the components and the environment according to whether the systems are abstract or concrete. We will also introduce the concepts of a subsystem and a level. More detailed analysis of the objects and properties will be done depending on whether the objects are material or abstract. We will introduce different classifications of properties: accidental and essential properties with the related concept of a type, structural and behavioral properties with the related concept of a dispositional ...