The use and suitability of design methods in practice : considerations of problem-solving characteristics and the context of design

Sammanfattning: Design by teams involves a variety of activities, such as prioritisation of projects, ideas generation, problem resolution, and concept selection. These activities are often practised in an intuitive manner. Companies generally feel insecure about the efficiency of their intuitive team design procedures, especially at the early stages of design. Traditionally, the engineering design field has developed design methods, many of which derive from observations of best practices in well-performing companies. Potentially, these methods have much to offer in the complex multi-objective product design activity; however, their impact on industry is considered insufficient. The reasons for a lack of transferability have largely been explored. Part of the research community has reported reasons like lack of computerised support, inadequate definitions, unsuitable scalability of examples, and inappropriate selection. Another part of the research community has abandoned the rational view and embarked upon the definition of a new paradigm of design, as initiated by Schön. Researchers embracing the ‘new’ constructivist paradigm do not see prescription as the primary way to support designers. Instead, they contend that the aim of research should be to understand design and assist what already exists. The objective of this thesis is to explore the impact of design methods in industry, and to study the use and suitability of design methods in practice, with an emphasis on the relationships between the design problem, the characteristics of design methods used, and the results from methods. The end goal with this research work is to explore the suitability of methods in practice, and how the design methodology field could be enhanced for a better support of designers in the world of practice. Early in the project, it was found that when designers use explicit methods, the results are not always satisfying, and that this dissatisfaction is sometimes caused by a mismatch between the explicit method used and design problem. A framework was created for matching design methods to design problems. In the case of convergent methods, the research has mainly been done while being located in industry, including active and passive searches. The research included studies of the use of methods, design problems, and the design context. Design methods were found to be used with modifications, sometimes leading to unreliable results, others to increased value of the method. The studies show that it is improbable that all possible problem conditions can be modelled and design steps prescribed, without overlooking important aspects of the design situation, and without inhibiting the unique creativity of designers. Therefore, the key to successful use of methods for concept selection cannot be on prescribing steps, but on properly educating designers who understand the need for good design practices, who know where to find good practice examples when required, and who know how to adapt (or even redefine) good practice examples to specific situations without risking the reliability of results. In the case of divergent methods, experimental research has been conducted to study the effects of idea-finding methods. In the experiment the effects that two types of methods, SCAMPER and visual stimuli, produced in team design were analysed by means of protocol analysis and outcome-based analysis. These effects were also compared to the effects of the traits of the team members. The methods were found to have a strong relative influence on team design. Aspects of the suitability of methods that are subjective, and aspects that are objective, have been found. The objectivity in the concept of suitability of methods is related to their problem solving capabilities and the characteristics of the problems at hand. There is also subjectivism in the concept of suitability of methods. They are only suitable if the potential users feel a need to use them. The methods are dependent on the individual and his needs.