In the fourth stage of the ergonomic design the “division of labor between segments of the organism” is designed. On the basis of anthropometric and physiological and also information- and cognitionpsychological realizations, activity elements and working equipment are improved for the functions of energy and power generation and the functions of the information absorption, processing, and delivery.
The model of user–computer interface, which is described in the following exempliﬁes the stage of ergonomic design. This model is based on the language model, which derives from Foley and van Dam (1982). The model supports the process of designing the user–computer interface and consists of four steps.
1. In the ﬁrst step (conceptual design), the user has to clarify how a task can be carried out with the help of a computer. At this level the structure of the fulﬁlment of a task is partially determined by the analysis of the task.
2. In a second step, the software functions are deﬁned. The functions inﬂuence the activities of the working person (semantic design).
3. In the next level, the user has to ﬁnd a way to solve the function. Therefore, the syntactic design deﬁnes the sequence of input and output. “For input, sequence is grammar —the rules by which sequences of tokens (words) in the language are formed into proper … sentences.” These input sentences are, for example, commands, names, coordinates, etc. The output tokens are often symbols and drawings
4. In the last step (lexical design), it is determined how these input and output tokens are formed
from the available hardware components. “We see, then, that lexical design represents the
binding of hardware capabilities to the hardware — independent tokens of the input and output
languages.” General strategies of the work system design, apart from this systematic, sequential proceeding, can be differentiated further and are described in the following.
Corrective and Conceptive Work System Design
In general, the design process of a work system has two variables:
- The changes (modernization, extension, etc.) of existing work systems
- The development of new work systems
From an ergonomic view the meaning of former type of design process is important, because existing work systems are frequently adapted to the (changed) requirements of human work (humanization measures). Such corrective measures of the work system design usually concentrate on ergonomic and/or organizational aspects (e.g., change of control elements, additional sound insulation, job enrichment, job enlargement). The importance of the conceptive work system design increases in connection with the introduction and establishment of the concurrent engineering approach or related concepts for the parallelism and/or integration of a product-, process-, and production system design.
One of the objectives is to consider the requirements of human
work in the draft stage and/or to anticipate the effects of design decisions. Differentiates between two kinds of conceptive work designs: “Preventive work design” as the mental anticipation of possible harming of the health and psychosocial impairment, and “prospective work design” as the conscious anticipation of possibilities of the personality development by the creation of scopes of activity, which can be used by employees in different ways. A prospective work design should result in motivation and enable learning through activities and tasks, which offer the potential for personal expansion and development.