## 2 State of the Art
### Vehicle Concept Development  
To design new or improved vehicle concepts, automotive manufacturers have created a product development process, which is similar among the various manufacturers (see [3], p. 5). At the beginning of this process, it is necessary to define the vehicle concept that will be designed and produced in later steps. On an abstract level, this vehicle concept development consists of four steps: customer-relevant properties, technical characteristics, vehicle concept, and target/actual comparison. During the last step, the desired vehicle concept results or an iteration loop is initiated due to the tolerated nominal/actual deviation [4; 5]. Figure 1 illustrates this vehicle concept development process:  
In the first step, the vehicle concept development engineer defines the customer-relevant properties. [PERSON] [6] describes them as the \"product's behavior\" from the customer's point of view. They summarize the value of the vehicle concept for the customer, which ultimately leads to his purchase decision [7]. As they reflect the customer's point of view of the vehicle concept, the engineer is not able to manipulate customer-relevant properties [6].  
As the mentioned process represents the current situation in the automotive industry, there are customer-relevant properties for conventional vehicle concepts. In a previous publication [8], [PERSON] defined three levels, \"whole vehicle level\", \"specification level\", and \"objectification level\", for structuring customer-relevant properties. On the whole-vehicle level, all of these are merged into the customer's overall experience. The specification level particularizes the unspecific whole-vehicle properties and quantitative attributes make them measurable on an objectification level. For example, the specification \"agility longitudinal dynamic\" is one aspect of the whole-vehicle property \"driving experience\", and one of the quantitative attributes is the \"maximum velocity\" [9]. For a complete enumeration of the conventional customer-relevant properties, the authors refer to [PERSON] [10], [PERSON] [9], and [PERSON] [11].  
The technical characteristics are the second step. The vehicle concept development engineer uses them to try to reach the desired customer-relevant properties, as they are adjustable [6]. In the given example, the maximum power of the engine would be a technical characteristic, which influences the maximum velocity. Hence, the technical characteristics are the engineer's view of the vehicle's components, which can be designed or selected.  
The result of the third step is the vehicle concept. Packaging thus determines the positioning of components. The vehicle concept is a design of the product idea based on compiling the essential parameters influencing the future vehicle.  
Finally, the values of the customer-relevant properties that are selected in the first step are compared with their current value in the vehicle concept as part of a target/actual comparison. If the deviation exceeds the tolerance, the technical characteristics should be adjusted.  
This paper deals with the customer-relevant properties of driving dynamics. It focuses, in particular, on the user as part of the customer. Therefore, the user's view of the vehicle and its dynamics is essential, while the technical implementation is neglected.  
Figure 1: Vehicle concept development process, adapted from [4; 5].