Purposeful, purposeful systems, Classification of...

Purposeful, purposeful systems

When studying economic, organizational objects, it is important to distinguish a class of purposeful, or purposeful, systems. In this class, in turn, we can distinguish systems in which goals are set from outside (usually this is the case in closed systems), and systems in which the goals are formed within the system (which is typical for open, self-organizing systems).

The patterns of goal-forming in self-organizing systems are discussed below. Techniques that help shape and analyze target structures are discussed in Ch. 5.

Classification of systems by complexity

There are several approaches to separating systems by complexity.

In the beginning, the terms large system and the complex system are used as synonyms. Some researchers attributed the complexity to the number of elements. Thus, WR Ashby considered that the system is large from the point of view of the observer, whose possibilities it surpasses in some aspect that is important for achieving the goal.

In this case, the same material object, depending on the observer's purpose and the means at his disposal, can be displayed or not displayed by the big system and, in addition, the physical dimensions of the object are not a criterion of assignment object to the class of large systems.

H. P. Buslenko suggested that, due to the lack of a clear definition of the classification of the system as a category of large and relative conventionality of this concept, connect the notion a large system with the role played in the study of the system complex system-wide issues, which, naturally, depends on the properties of systems and classes of problems to be solved.

This view was also taken by the authors of the first in our country textbook on the theory of large control systems.

For the spheres of biological, economic, social systems, sometimes the notion of a large system was associated more with the concepts of emergence, openness, activity of elements, important for such systems, as a result of which such a system has, as it were, freedom volition ", unstable and unpredictable behavior and other characteristics of developing, self-organizing systems.

B. S. Fleishman as the basis of the classification takes the complexity of the behavior of the system.

At the same time, there are other points of view: since these are different words in natural language, then they need to be used as different concepts.

However, some authors link the concept of " large with the value of the system, the number of elements (often relatively homogeneous), and the notion complex - with the complexity of the relationships, algorithms.

There are more compelling reasons for the difference in the concepts of " large system" and complex system.

In particular, Yu. I. Chernyak suggests calling a large a system one that can not be studied otherwise than with the subsystems a - such a system that is built to solve a multi-task, multidimensional task .

Explaining these concepts on examples, Yu. I. Chernyak emphasizes that in the case of large systems, the object can be described as if in one language, ie. with a single modeling method, albeit in parts, subsystems (Figure 3.16, a). A complex system reflects the object "from different sides in several models, each of which has its own language & quot ;, and for coordination of these models a special metalanguage is needed (Fig. 3.16, b).

Big and complex systems

Fig. 3.16. Large and complex systems

The concepts of a large and complex system Chernyak connects with the notion of an observer: to study a large system, you need an observer i/in view of not the number of people taking part in the research or design of the system, but the relative homogeneity of their qualifications: for example, an engineer or an economist), and for understanding an complex system - you need several , observers ", fundamentally different skills (for example, mechanical engineer, programmer, computer scientist, economist t, and, perhaps, a lawyer, a psychologist, etc.).

It emphasizes the presence of a complex complex system, a complex composite goal. or even different targets and "simultaneously many structures from one system (for example, technological, administrative, communication, functional, etc.)". Later, Chernyak clarifies these definitions. In particular, when defining a large system, it introduces the notion of a priori allocated subsystems, and in the definition of complex - the concept of incomparable aspects of the characteristic of the object and includes in the definition the need to use several languages ​​and different models.

One of the most complete and interesting classifications by complexity levels is offered To. Boulding . The levels identified in it are given in Table. 3.3.

Table 3.3

Classification of systems by C. Boulding

System Type

Difficulty level

Examples

Concepts, models

Live Systems

Transcendental systems or systems that are currently outside our cognition

Integral concepts

Social Systems

Social organizations

Sociological concepts

Integral concepts

Systems characterized by self-awareness, thinking and non-trivial behavior

People

Physiological, psychological concepts

Living organisms with more developed ability to perceive information, but not possessing self-awareness

Animals

Biological concepts and models

Living organisms with low ability to perceive information

Plants

Chemical and biological concepts and models

Open systems with a self-preserving structure (the first stage, on which separation into living and non-living is possible)

Homeostat, cells

Non-living systems

Cybernetic systems with controlled feedback loops

Thermostat

Simple dynamic structures with a prescribed law of behavior

Hourly mechanism

Static structures (skeletons)

Crystals

Physico-mathematical concepts and models

In the classification of K. Boulding, each subsequent class includes the previous one, characterized by a greater manifestation of the properties of openness and stochastic behavior, more pronounced manifestations of regularities of hierarchy and historicity (see paragraph 1.5), although this is not always noted, but also more complex mechanisms functioning and development.

Assessing the classification of systems from the point of view of their use when choosing methods for their modeling, it should be noted that such differences (up to the choice of mathematical methods) are available only for classes of relatively low complexity (in the classification of K. Boulding, for example, for level of inanimate systems) for which models based on the fundamental principles of automatic control theory can be applied, software control, deviation control (feedback model), a model that combines the principle of control over deviations and compensatory control (or proactive control) by including in the model a block of compensation that measures interference and makes recommendations for correcting the control law.

For subsequent classes of complex systems, it is stipulated that it is difficult to give such recommendations. It is interesting to note here that the sign "information exchange with the environment" is selected as the classification criterion, and then the symptom "presence of consciousness" is added. and self-awareness .

In the search for a classification that would help in the initial stages of modeling to determine which class of systems is more in line with the simulated situation, a classification was proposed in which an attempt is made to link the choice of modeling methods to all classes of systems. The basis of this classification is the degree of organization.

thematic pictures

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