Humans in Work System Environment - Fundamentals and Assessment Tools for Occupational Ergonomics - page 65

to the death of bacteria under the influence of light or disinfectants, to the consumptions of an animal by
starvation, and to the decrease of an animal or human population where death rate is higher than birth
rate.” The discovery of this phenomenon of “isomorphy of laws” in the different scientific fields caused
Ludwig von Bertalanffy to aim for a “Unity of Science” with help of the “General System Theory.” It was
apparent to him that this ambitious goal could only be achieved — if ever — in the inscrutable future.
His proceeding is marked mathematically. A standardization of the sciences is finally seen by him as the
“reduction of all science to physics, in the final resolution of all phenomena into physical events.”
The system approach of cybernetics (Wiener, 1961) was developed at about the same time as the
“General System Theory.” This approach is likewise mathematically formed. Wiener and others under-
stand cybernetics (Greek: “kybernetes” steermanship) as the “entire field of control and communi-

cation theory, whether in the machine or in the animal” (Wiener, 1961). The cybernetics takes up
concepts of feedback, regulation, and control and interprets social systems in a cybernetic way.
Methods, procedures, and realizations of the (automatic) control engineering are generalized and
applied to nontechnical concepts. A process is described with the control loop, which functions auton-
omously on the basis of the exact given premises. A desired value is given to the system. If it comes to a
disturbance, the system implements prior defined corrections autonomously, in order to achieve the pro-
grammed specified condition again. The system compensates any environmental changes with self
change. It experiences information about required changes via feedback of the results of its procedures.
Figure 5.1 shows an example of a control loop with reference to the handling of a boat (Frank, 1964). The
boat can be interpreted as a socio-technical system. The captain formulates the destination. The pilot
determines the particular location (current status) and composes a program to transfer the current
status to the desired status. He has to “save” the desired status, to measure the current status, to
compare the two values and to derive a program. This program has to be conveyed to the steersman
by the pilot in terms of individual decisions (so-called “determined” decisions). The steersman transfers
these orders into navigation positions.
Self-regularization, adaptation, and learning aptitude are, therefore, system specifications, which are
examined by the cybernetics. The cybernetics discusses for the first time the relationship between
system and environment as a problem of constancy and change. In the center of the considerations
the question is formed, how system constancy can be maintained in a changing environment. For the

¼

captain
destination

target situation

pilot
data processing and planning

actual
situation

steersman
steering

rower/ power engine
working physically

environment

FIGURE 5.1 The socio-technical system “boat” as an example of a control loop.