Dynamic Properties of the System

Let us consider the second group of system properties called dynamic properties.

If we consider the state of the system in another, different from the first, point in time, we will again discover all four static properties. But if you impose these two “photos” on each other, then you will find that they differ in details: during the time between the two moments of observation, some changes occurred in the system and its environment. Such changes can be important when working with the system and, therefore, should be reflected in the description of the system and should be taken into account while working with it. The features of changes with time inside and outside the system are referred to as the dynamic properties of the systems. If static properties are what you can see in the photo of the system, then dynamic properties are those that are found when watching a movie about the system. We can speak about any changes in terms of changes in static models of the system. In this regard, four dynamic properties are distinguished.

Functionality is the fifth property of the system. The processes Y(t) occurring at the outputs of the system {Y(t) = {y,(0, y₂(t),..., y„(0K Figure 2.5) are considered as its functions.

Functions of the system are its behavior in the external environment, changes made by the system in the environment, the results of its activities, and the products manufactured by the system.

From the multiplicity of outputs follows a plurality of functions, each of which can be used by someone for something. Therefore, the same system can serve different purposes.

A person using the system for his own purposes will naturally evaluate its functions and put them in order in relation to his needs. Thus, the notions of main, secondary, neutral, undesirable, superfluous functions appear. Note that these terms are evaluative, subjective, and relative. Thus, the main function of a lamp is considered to give light, but when choosing a lamp from dozens of others sold in a store, its decorative qualities, consistency with the interior of the room, its cost, etc. come to the fore.

Therefore, we single out two points of this property of systems: objective plurality of functions and subjective ordering of functions.

Liability to stimulation is the sixth property of the system. At the inputs of the system, certain processes X(t) = [xft), x₂(t),..., xjt)} also occur, affecting the system, turning (after a series of transformations in the system) into Y(t) (see Figure 2.6). Let us call impacts X(t) stimuli, and the susceptibility of any system to external influences and change in its behavior under these influences will be called liability to stimulation.

By the way, the word “stimulus” in ancient Greek means a stick for urging on a donkey.

The variability of the system over time is the seventh property of the system. In any system, there are changes that need to be taken into account to foresee and incorporate into the project of a future system; to promote or counteract them; and to

FIGURE 2.5 Processes at outputs are functions of a system.

accelerate or slow them down when working with an existing system. Anything can change in the system, but in terms of our models, we can give a clear classification of changes: the values of internal variables (parameters) Z(t), the composition and structure of the system, and their combinations can change (see Figure 2.7).

The nature of these changes may also be different. Therefore, further classifications of changes may be considered.

The most obvious classification is by the rate of change: fast or slow (compared to something taken as standard); it is possible to introduce a larger number of gradations of speeds (superfast, very fast, etc.).

Of interest is the classification of trends in changes in the system regarding its composition and structure. We begin this classification with the introduction of special concepts, considering the changes in a short time interval, so that the changes can be considered to go in “one way”, that is, monotonous.

We can talk about such changes that do not affect the structure of the system: some elements are replaced by other equivalent elements, and parameters (internal variables Z(t)) can change without changing the structure (clock, city transport, school, theater, etc., they “work”). This type of system dynamics is called its functioning.

Further, changes can be primarily quantitative: the number of parts (system’s composition) grows, and although its structure changes automatically, for now it does not affect the properties of the system (extension of a landfill or a graveyard are examples). Such changes are called system growth.

Then allocate qualitative changes in the system, in which there is a change in its essential properties. If such changes go in a positive direction, they are called development. With the same resources, the developed system achieves better results, and new positive qualities (functions) may appear. This is associated with an increase in the level of organization of the system.

As applied to organizational systems, R. Ackoff defines development as “an increase in desires and the ability to satisfy one’s own and others’ needs and justified desires”. (Desires are called “justified” if their satisfaction for the sake of some does not negatively affect the development of others. Needs are what is necessary for survival. Different combinations are possible: for example, you may not want the needed, and you may wish the unnecessary).

How much a subject (individual or organization) has is a matter of accumulated wealth. An indicator of wealth is the standard of living. But the question of what we can do with what we have is a question of competence, that is, what we have learned.

FIGURE 2.7 Changes in the system may consist of changes in composition either in structure or in both.

And this is expressed by the quality of life achieved. The more developed is the subject, the less resources he needs to achieve a satisfactory quality of life, or the greater the quality of life he can achieve with what he has.

Therefore, growth occurs mainly due to the consumption of material resources, that is, development caused by the assimilation and use of information. Growth is an increase in the size and number of parts. Development is an increase in competence. Bulk is the result of growth; competence is the result of development. The purpose of the growth of the organization is to improve living standards. The purpose of development of the organization is to improve the quality of life.

Growth may inhibit development, but development cannot restrain growth. Growth and development can go simultaneously (as in a child), but are not necessarily linked. Growth is always limited (due to external physical conditions, in particular, limited material resources), and development from the outside is not limited because information about the external environment is inexhaustible: no matter how much we know, there is always something else that is unknown. Lack of material resources can limit growth but not development.

However, there is an internal constraint on development. The fact is that development is the result of assimilation and use of new information, that is, the result of training is learning outcome. But learning is perhaps the only action that cannot be done for and instead of the learner. If the person does not want to learn, it will not, and cannot, develop. From the outside, it is impossible to develop the system; you can only help in the development, but provided the propensity of the system to learn. Development is possible only as self-development.

It is clear that in addition to the processes of growth and development, reverse processes may also occur in the system. Reverse growth changes are recession, contraction, and reduction. Reverse development is called degradation, that is, loss or weakening of useful properties.

We have considered the possible monotonic changes of the systems (see Figure 2.8).

Obviously, a monotonic change can’t last forever. In the history of any system can be seen periods of decline and recovery, stability and instability, the sequence of which forms the individual lifecycle of the system.

The concept of lifecycle deserves special discussion because both in the design of future systems and in the study and management of existing systems, information about the individual history of the system plays a very significant and often decisive role in achieving this goal.

When describing the lifecycle, special attention should be paid to the continuity of its trajectory. Put differently, it is necessary to determine the lifecycle in the past and the future. The past history is restored according to the information available to us. Unfortunately, often this information is incomplete, inaccurate, and about some periods completely lost. Therefore, the description of past events often inevitably has irreparable gaps (an example is the biography of Jesus Christ contained in the Gospels). But when determining the future lifecycle of a designed system, continuity should be a special concern: the planned history of this system will end at the first gap in the description of its lifecycle. There are many examples of this. The carelessness of the stage of disposal of obsolete fluorescent lamps has led to the fact that mercury enters the soil and water from broken lamps in landfills, poisoning all living beings. The ill-conceived stage of connecting the cables of the space rocket ended with the fact that the ship sent to Mars did not open the antennas because of incorrectly connected signal cable, and all the billions of dollars spent on the project went to waste. How many crop death cases were due to the omission of a single stage of its lifecycle. There should be no gaps in the description of any technology.

Further, while describing the processes occurring in the system, you can use their other classifications, for example, classification by predictability: deterministic and random processes. Or classification according to the type of time dependence: monotonous, periodic, harmonic, impulse, random, chaotic, etc.

Existence in a changing environment is the eighth property of the system. Changes not only in this system, but in all the rest. For this system, it looks like a continuous change in the environment. The inevitability of existence in a constantly changing environment has many consequences for the system itself, starting with the need to adapt it to external changes in order not to die, to various other reactions of the system.

When considering a particular system for a specific purpose, attention is focused on some specific features of its response. For example, consider how the rate of change within a system should relate to the rate of change in the environment — should it be slower, match, or go faster? This is determined by the nature of the system or its purpose. For example, for systems designed to transfer information in time (books, monuments, works of art, video and audio recordings, triangulation marks, etc.), the slower they change with changes in the environment, the better they perform. Another example of this is the preservation of its state by automata and living organisms (homeostat, stabilization, stationarity). A new reaction of living organisms goes almost simultaneously with changes in the environment, for example, the adaptation of the pupil with changes in lighting. There are systems whose functions can only be performed if changes made in the system are faster than the changes in the environment. Management is a typical example: the search and comparison of various control actions must occur at an accelerated rate so that the selected effect proceeds in real time.

We note another important feature of the existence of the system in a changing environment. The changes themselves are constantly changing; this is reflected in the acceleration of changes in the environment. For example, the speed of movement in space, the transmission and processing of information, and production and consumption of products during our generation has increased more than that in all the prehistory. This requires rapid and significant changes in what we do and how we do it. People, organizations, firms, and governments that are adapting to the changes poorly leave the stage and drop out of the game. The only chance to survive in a turbulent environment is to provide a dynamic balance, like a ship or plane caught in a storm. And the stronger the external changes, the more actively the internal changes should be carried out (compare the driver’s activity on good and bad roads, in good and bad weather). Although forecasting and training remain important means, developing immunity to changes beyond our control and strengthening control over others are considered to be more effective.