Humans in Work System Environment - Fundamentals and Assessment Tools for Occupational Ergonomics - page 85

of the realized work system, however, is still necessary; the correctness of the obtained assumptions
and forecasts must be verified with consideration of the individual characteristics of the working
persons (see also for this stress-strain concepts in Luczak and Rohmert, 1997).
5.4.3 Sequential and Integrated Work System Design
Concerning the temporal reference with which the individual design range of technology, technique,
ergonomics, and organization are processed two further strategies can be differentiated: the sequential
and the integrated work system design (see Kirchner, 1972). The characteristic of the sequential work
system design mentioned earlier — is that the design ranges are worked on gradually in a phase con-
ception. (A conceptive design presupposes naturally that all phases will go through the thought
process first before the work system is realized.) A fundamental problem consists, however, of the fact
that the design levels are not independent of each other. Generally the decision made in a planning
phase for a design condition limits the decision range of the following planning phases. The advantage
of the transparent planning process, which limits the complexity is always faced with the disadvantage
that interdependences between the design ranges are not considered necessary. It is criticized further
that sequential concepts usually begin with the technological work system design and the following
decisions are a subordinate of the selected technological concept (technological determinism).
This determinism can at least be partly avoided by iterative procedures, that is, by the installation of
feedbacks and presumptions:
. Feedbacks: if no satisfying solutions can be found in a design phase, completed phases are repeated
in the form of a loop and new insights can be integrated
. Presumptions: in each design phase the consequences are anticipated, which leads to a respective
decision in the following stages of the design
The iterative design represents the transition towards integrated work system designs. The concept of
the integrated work system design provides for a simultaneous processing of the four design stages, in
contrast to the sequential work system design (Kirchner, 1972, 1993, 1997). Ergonomic problems and
aspects of the work organization are to be considered in particular with reference to technological and
technical determinations. A goal is to consider reciprocal effects from the beginning and avoid the com-
pensatory measures, which are accomplished in the sequential design process. Compensatory measures
abolish unwanted secondary conditions of proceeding decisions (Luczak, 1998). Due to the complexity of
the planning process interdisciplinary planning teams are necessary for the realization of such an inte-
grated approach (Luczak, 1996).
5.4.4 Technocentric and Anthropocentric Work System Design
Every decision made concerning the mechanization degree of a work system also means a determination
of the function division between humans and operating resources. This allocation process can orientate
itself towards different criteria. The spectrum of design strategies is clarified on the basis of two typical
conceptions: the technocentric and the anthropocentric design strategies (Br ¨ dner, 1986).
The aim of a technocentric design is to attain an operating goal (production of goods or services) poss-
ibly independent of the requirements of manpower. The intention of the approach is to reach a high
degree of mechanization and automation. The remaining work carried out by humans is characterized
by a large amount of division in labor, in order to reach a high exchangeability in the workforce. Human
work itself is a subordinate of technical requirements (e.g., cycle time) and is regarded in principal as a
potential interference factor. A goal, in the long run, is a fully automated production.
In contrast, an anthropocentric design proceeds from the requirements of the workforce. Humans are
perceived as a complex nature whose needs are to be considered during the work system design. Activity
elements, which are helpful to this idea of man are carried out by humans, all others are transferred to the
technical system. The goal is that the technology subordinates to the human (in particular also the