About

Preface of the Editor

 Problem

 Today’s companies are exposed to competition in a global market and ever rising expectations of customers. These circumstances compel companies to be innovative and – at the same time – to minimize the time to market.
 Digital design tools seem to provide the opportunity to realize ever shorter product cycles. The CAD model may be regarded as the center of a digital design environment. The evolving model can be managed by PDM-systems and handed over to various design and production processes. Thereby, it allows for the development of highly complex products in concurrent and distributed design processes. Yet, these circumstances do not necessarily enable innovation. Innovation requires new ideas and the development of ideas demands creativity.
 The most common design tool for that purpose eludes from the digital design environment: the paper sketch. The sketch is probably the most powerful design medium for the development of conceptual design ideas. Yet, there had not been enough knowledge about its mode of functioning in order to develop a digital counterpart of that design medium. While today’s CAD-systems are further developed, the gap between the paper sketch and CAD is getting wider and wider.

 Objectives

 The overall goal of this thesis is to provide comprehensive insight into the complex processes of creativity that take place when sketches are used for conceptual design. From this insight, the basic characteristics of sketching media emerge, so new sketching tools, which are both effective and efficient, can be developed. For this purpose, the use of different design media in industry is investigated by the help of two surveys. The sketch, which has been indicated as being most helpful for idea development, is investigated in great detail by the help of 120 design experiments. On the basis of the experimental results, a comprehensive framework for regarding the process of sketching is developed.
 Moreover, the requirements are formulated, which need to be met by a future medium for conceptual design. The 3D-sketcher, which is the prototype of a digital sketching tool, shows that it is possible to meet these requirements in one new medium.

 Results

 The surveys among designers have shown that CAD and sketches are both integral parts of design. Sketches mainly serve for idea development, while CAD is rather used for concretion, verification and documentation purposes. Hence, the impact from CAD on the efficiency and effectiveness of conceptual design is rated lower than the impact from sketches.
 The experimental study has revealed that conceptual design sketches may contain elements on various levels of abstraction. Those different levels of abstraction may be mixed up and combined within a single sketch. Moreover, the elements within a sketch show linguistic characteristics, so they may be compared to words in a sentence. The relations between the elements in a design sketch bring about highly complex technical “stories,” that even pose questions or represent irrational statements. Visual perception and the sequential character of depiction may cause the reinterpretation of those “stories,” so the designer may discover completely new concepts within his own sketch. The efficiency of the sketching process is increased by the way that the pencil-tip is moved through the sketch, especially when the designer is not actually drawing any line.
 In order to integrate all these findings into one consistent framework, the sketching process needs to be regarded as the designer’s communication with himself. That framework is used to elaborate those characteristics of the paper sketch that make it such a powerful tool for conceptual design. A new sketching medium needs to meet certain requirements in order to be an adequate equivalent for paper sketches. Still, such a medium is also constrained by the digital design environment.
 The 3D-sketcher is the prototype of a digital sketching tool that has been developed at the Institute of Product Development at the Technical University in Munich. It features a very simple functional principle that meets the requirements mentioned afore. By the help of virtual reality, this device allows for the creation of a conceptual sketch that is truly spatial. A desktop-based version of the sketcher is suitable for a usual office surrounding. Still, when used with different hardware configurations, this medium may be applied to other purposes and disciplines.

 Consequences for industrial practice

 Designers, design managers and CAx-managers may benchmark their design environment by the help of the survey results on the industrial use of design media and tools. The designers critically evaluate their actual CAx-tools and make demands on future tools. Softwaredevelopers should carefully consider these statements when they intend to improve actual CAD-systems or develop new design tools. The elaboration of the functional principle of conceptual design sketches should inspire designers to reflect and improve their own sketching techniques. Moreover, the demonstration of the effectiveness of sketches should encourage designers to use this medium until there is a comprehensive equivalent at hand.
 The 3D-sketcher is a medium that is capable of replacing the paper sketch sooner or later. As a stand-alone system, the sketcher could be used in a productive manner in the near future. Ideally, the functional principle of the sketcher is integrated into future CAD-system, so sketches can be used at any step of the design process, right within the CAD-model. Workshops with designers, design manager, CAx-managers and software developers are actually carried out at the Technical University in Munich in order to discuss all the matters mentioned afore.

An Introduction to Sketching in Mechanical Engineering

 At the Technical University of Munich, a workshop was held that aimed to bring together designers from industry and developers of design software. At that workshop, a designer, who worked at an automotive supplier for clutches, stated that he would like to be more creative in his design work. Yet, he complained that the design software restricted him in doing so. On this complaint, the representative of a company that distributed one of the major software packages responded that “for a supplier, the restrictions from the automotive manufacturer are so severe, that there is no room for creativity anyway.” This reply may reveal a potential major misunderstanding of creativity. This designer may not be designated to invent a new functional principle for clutches, but does he therefore not need to be creative?
 In mechanical engineering, creativity does not only take place in design from scratch and a creative solution does not necessarily need to include some revolutionary new functional principle. Strong restrictions may exclude the development of new functional principle and may necessitate the reuse of a highly optimized working principle. The adaptation of a given main solution may still require new concepts for subsidiary systems and therefore demand creativity in particular. Conceptual design does not need to occur only when it has been planned to occur. At the very least, methods and tools for design should not distinctively preclude the emergence of new conceptual ideas.
 The designer’s statement quoted above also reveals the dissatisfaction of designers with their design tools’ support of creativity. Innovation has always been a driver for technological, economical and social progress. Computer-aided design tools have surely paved the way for the development of today’s products; yet, they do not create the corresponding ideas. At the time being, it is still the designer, who comes up with new ideas and who has done so at all times – even before computers were invented. But there is another design tool, which has been in use for a much longer time and still serves as a powerful design aid (as we will see in the course of this thesis): it is the ordinary paper sketch.
 A sketch is available almost everywhere at any time– even when it is actually just a napkin or a beer coaster. Researchers who investigate design disciplines other than mechanical engineering (such as architecture1 ) often emphasize the benefit from sketches for creative design. This tool supports the occurrence of design ideas in manifold ways, although it is a rather simple device itself.
 But what is the state of affairs in the case of mechanical engineering? Should the dissatisfied clutch designer use sketches in order to be more creative? And if he still needs to use computer-based design tools (which is likely to be the case), then how should sketches interact with those tools? Let us consider one finding from the following thesis beforehand: Sketches and computer-based tools both play important roles in today’s design processes in mechanical engineering. However, there is no sufficient methodological and technological framework that integrates both these design tools in such processes.
What needs to be clarified, is the particular benefit that may be derived from the use of sketches in mechanical engineering. Moreover, the mechanisms of problem solving that are facilitated or even enabled by the sketch need to be revealed and understood. On basis of such an insight, those characteristics, which actually determine effectiveness and efficiency of a sketch as a design tool, may be identified. Only then may sketches best be integrated into today’s and tomorrow’s design environments. The development of a new type of digital design device that combines the advantages from paper-sketches and computer-based tools in one single medium would be possible. In the following course of this thesis, we will regard findings from a four-year research project that has dealt with all these subjects.
The project was a cooperative effort between researchers from the areas of mechanical engineering1 and psychology2 studying future tools and media for conceptual design3 . The researchers carried out two surveys, several workshops and more than 120 experiments with students and designers. Based on the results from these activities, the prototype of a new type of future design tool was set up. The so called “3D-sketcher” allows for the creation of “truly” spatial sketches in a completely intuitive way with the help of Virtual-Reality-technology.
In the second chapter, we will explore some scientific background from both the areas of design and psychology. At first, we will clarify the term “conceptual design” in general (as far as possible and necessary). Starting from a look at the human mind from the angle of cognitive psychology, we will explore design as a series of actions, as problem solving and as an application of creativity. Against this background, we will regard the support for design processes that is offered from engineering design methodology.
The third chapter provides a closer look at common media and tools for conceptual design in mechanical engineering. A survey is presented that highlights the way in which those media are applied by designers from industry. It elaborates the benefits and drawbacks from the use of sketches and computer-based tools, as well as the designer’s claims against future design media. Based on these results and on some theoretical consideration, we will get to know a scientific framework that will help us to fit together the experimental findings from the next chapter.
The results from an extensive experimental study on the use of sketches in mechanical engineering are presented in chapter four. We will start from statistical analyses that examine commonalities and differences between the sketching behaviors of 61 designers and students, respectively. Based on these results, we will choose some very characteristic experiments for further analysis by means of case studies. While viewing vivid design sequences and actual design sketches, we will go further and further into the details of creative conceptual design with the help of sketches. We will gain insights in various ways to depict abstract and even irrational information entities and how these entities are arranged in sketches like the words of a “graphical language.” The perception and interpretation of design sketches and the way these processes may lead to the (unintentional!) occurrence of new conceptual ideas will be a subject matter. Even a single motion of the pencil, which spans only a fraction of a second, contributes to the efficiency of the use of sketches for conceptual design. In summary, numerous different aspects of sketching can be identified that interact and make up this unique design medium.
As a consequence, we will get to know the concept of the “3D-sketcher” in chapter five. This future design medium aims to comprise the characteristics of classical sketches and the advantages from digital environments. This medium provides very intuitive creation and handling of sketches with the help of Virtual Reality. Such 3D-sketches provide completely new ways of representing any kind of spatial abstract information. Considering the actual prototype of the 3D-sketcher as just one example, we will consider other possibilities to configure such a medium. Thereby, we will explore several different applications of the sketcher in mechanical engineering as well as in other design-related and even artistic disciplines.
After having gone through this thesis, we may not be able to answer all the questions that we raised some paragraphs before with one hundred percent confidence. However, this is not the goal of this thesis. It is probably neither possible to treat such an extensive subject within one thesis, nor possible to achieve necessary results in one research project. In the first place, the objective of this thesis is to open up a comprehensive framework that allows for correlating all the different factors involved in sketching. That framework may be used for discussion, reasoning and forming one’s own mind about this interesting subject. Thus, it may help other researchers to generate hypotheses and set up research projects about sketching, creativity and conceptual design. Nevertheless, this framework may help students and professional designers to reflect upon their own procedures in order to work more creatively and efficiently.
Beyond this framework, this thesis provides numerous well-founded hypotheses about sketching in design that could not be verified within this project. These hypotheses are open for verification, modification and even refutation by anyone. Yet, there are also a number of scientific findings that were gained, verified and which are presented in depth in this thesis. These results may well be used within other research projects that deal with subjects that are related to sketching and creativity. They may also be used by the developers of soft- and hardware for design in order to ensure the applicability, effectiveness and efficiency of their future products. The presentation of the 3D-sketcher and its functional principle especially aims in that direction. Again, these results may be of great interest for designers and designers-to-be in order to better understand those parts of their challenging profession that elude from conscious perception.
Lastly, this thesis provides a number of vivid examples of real sketching processes that may even arouse interest in a reader who is not directly related to this interesting topic.