Aerodynamics and design, considering the packaging aspects influence almost all areas of development of the body. The figure shows the interrelationship between the various parameters of structural design.
Apart from rational considerations such as fuel consumption, driving performance and availability of space, the body form and design as well as the design of the interiors are decisive criteria for the success of an automobile in the market. Hence the design contains a significant proportion of the value of a vehicle.
The term design (of lat. signum = feature) is defined as follows:
"Design is the process of the adjustment of an article to the physical and psychological needs of humans. "
According to this definition, the design of a motor vehicle has three substantial functions:
· Practical function
· Aesthetic function
· Symbolic function
The practical functionality is ensured by the appropriate application of ergonomic criteria and specifications (form follows function), while the appearance fulfils the aesthetic function. The symbolism is primarily determined by the value of the product in the market or the value held by the target group. Here, an interdependence is natural as these three basic functions do not generally occur independent of one another.
The conceptions of the design department primarily depend on their own aesthetic conceptions and also on that of the targeted spending group or the user group. The design department has to put itself in their place and let their subliminal ideas or conscious conceptions flow into the design of the vehicle.
In order to arrive at an accurate picture of the requirements and desires of the customer or user, the user group can be classified under demographic and psychological features. The demographic criteria for example contain the following data:
· Age
· Sex
· Physical status
· Nationality
· Qualification
· Occupation
· Place of operation of the vehicle
· Season of operation of the vehicle
· Operating period of the vehicle
The demographic features highlight the operational and usage requirements and thus describe the requirements of a vehicle based more on the "noticeable" proportion-use-value. The requirements of the user group on the "obvious" proportion-use-value, visibility and recognition demands will be determined by its psychological orientation.
Examples of the psychological typologies are:
· Prestige orientation
· Safety orientation
· Orientation towards innovation
· Performance orientation
· Aesthetical orientation
· Sensitivity orientation
· Minimum expenditure orientation
· Traditional orientation
Different models are available, which describe the variation and individuality of human beings; the number of basic types usually number six to eight.
The design department can imagine a profile for its customer based, among others, on the above mentioned criteria and allow for its conscious or subliminal imagination to flow into the design of the vehicle.
Two basic concepts for design exist. In the 'Generation concept', all vehicles of a particular generation exhibit similar features (e.g. OPEL or " New Edge" design from Ford). In each generation, a new beginning is hence possible. The risk of non-acceptance of the first model of a new generation is quite high, since a huge step has to be taken in order to still be up-to-date even with the last model of this generation. The 'Evolution concept' represents an alternative. Each new model represents a step further to the previous (e.g. Mercedes, BMW). On one hand the continuity and steadiness can be expressed as symbolic to the brand, while on the other hand, design is subjected to temporary trends and this can hardly be satisfied by the evolution concept.
