2. Classification of Systems

The objective reality shows an example of united material system. During research, it is subdivided into local systems: biological, social, economic, ecological, physical, chemical, etc. The above-mentioned systems are grouped into:

• abstract and concrete,

• natural and artificial,

• social, machine and “man-machine” systems,

• open and closed systems,

• permanent and temporary,

• stable and unstable,

• determined and probable.

Abstract and concrete systems. The system is called abstract if its elements are abstract notions. Abstract systems are connected with theoretical structures and are composed of ideas, for instance, economic theory, theory of probability, etc.

Concrete (real) systems are functionally related elements (men, machines, materials, energy resources and other physical objects). In transport industry, concrete systems are: system of freight transport, system of public passenger transport, spatially limited transport systems, etc.

Natural and artificial systems. Natural systems are connected with nature. Every living body is a unique natural system (for example, solar system).

Artificial systems emerged when people gathered in groups to hunt and live together for the first time. Now, artificial systems constantly emerge in many variants, from production systems of a road transport enterprise to a space exploration system.

Social, machine and “man-machine” systems. Systems composed of people are referred to as purely social. Industrial, transport and other enterprises, political parties, technical societies serve examples of social systems. However, it is hard to imagine any system of people who do not use at least the simplest equipment. Therefore, most concrete systems belong to the subgroup of “man-machine” systems.

Purely machine systems are supposed to produce their output data and maintain their functioning, i.e. to be capable of adjusting to the environment.

Open and closed systems. Opensystemsareclosely related with other systems which influence each other. In other words, open systems are interacting with the environment.

Systems containing live organisms as their components are referred to as open. Transport systems function within bigger systems and thus, are open systems.

In open systems, the same state can be reached at various initial data due to interaction with the environment. Opensystemsaredividedintoadaptableandnon-adaptable.

Closed systems do not interact with the environment. The state of closed systems depends on their initial data. If the data changes, the final balanced state of the system will shift as well. Any try to regard open systems as closed systems, when the environment is not taken into consideration, may be very dangerous.

In reality, closed systems are hard to find. There are numerous applications of closed systems in research and laboratory experiments to simplify analysis of some production situations.

Permanent and temporary systems.Permanent systems denote systems existing for a long period of time in comparison with the limited time of human activity within those systems.

Temporary systems have great importance in specified problem solving and are created for a given time period to be terminated later (e.g. vehicle caravans for transportation of harvested wheat).

Stableandunstablesystems.A system is considered to be stable,if its parameters and functions do not significantly change or the changes take the form of repeated cycles (e.g. the system of regular international freight or passenger transportation). A research and development laboratory serves an example of an unstable system.

Determined and probable systems. A determined system defines a system where the components interact in an exactly forecast mode (e.g. a sewing machine). If the previous output data and operation program of the determined system is known, the future status of the given system is easy to predict.

Computers, automated systems and automated enterprises are determined systems. Any deviation from the prescribed mode of operation is considered to be a malfunction or an accident.

Probable systems are difficult to predict. It is possible to forecast with due probability how the system reacts for the given parameters. Transportation systems are referred to as probable systems. They require methods of management which maintain survival and functioning of the system in the conditions of the changing environment. Probable systems need to adjust to the given economic, financial, social and political environment. Such systems are supposed to learn from the previous experience.

Subsystems and Suprasystems in Transport

Any system is included into a bigger system. Thus, a road transport enterprise is a part of an industry. The given industry is an element of the national economy which serves a part of the entire society. The national society becomes a component of the global community, whereas the global system is included into the solar system, etc.

Transportation enterprise is regarded as a system only if the focus in analysis is on transportation of freight or passengers, and if the enterprise is composed of all objects, features and relations required for achieving the given goal at a defined number of limitations. Smaller systems within such system are called subsystems.

The term suprasystem is applied exclusively to large and complicated systems. Asystem needs to meet the requirements of the bigger systems where it is included.