On Material selection and its consequences in product development

Sammanfattning: Technological development, and increased demands on sustainable solutions, have impacted the development of new products. New products need to be more efficient, and there are increased possibilities for a more diversified and informed decision regarding what materials are used in the product. However, how can engineers and designers be helped in their efforts to make better decisions regarding materials?In this research, carried out via multiple case studies and action research, behaviors regarding material selection and material management are examined. The data has been collected using participation action research, observations, and interviews as the primary sources of information. The author has conducted participation action research integrated into an industrial environment, multiple case studies using students in industrial design engineering have been done, and the researcher has performed interview studies with industry representatives. The behaviors described in the empirical studies are contrasted with basic decision theory and analysis of established product development methodology, asking the questions: Are basic assumptions built into models and methods taught to designers and engineers valid?The research presented in this thesis shows that there are personal, technical, and organizational aspects to selecting and managing materials in product development. This work has also shown that assuming rationality, something that is built into methods and models as well as taught to engineering students, is not valid in decision-making; human beings are not rational, and entirely rational decisions are not possible due to the vast data and prediction needs to be able to make entirely rational decisions. Even when assuming some variant of bounded rationality, multiple factors described in decision theory are not acknowledged in product development methodology. Two of these can be described as identity (both personal and professional) and mental models of materials.The discrepancy in how decisions are described in decision theory and how methods for decision-making are designed in product development risks inhibit the introduction of new and more sustainable materials in products. This could be because non-rational aspects of decision-making are incorporated in the decision-making under the assumption of rationality. It could also be because of the mental models of materials affecting what the designers and engineers think they can do with a particular material. These behaviors make the risks of introducing new materials too big for a designer or engineer to accept.Outcomes from this research show that additional data will not be enough to persuade designers and engineers to select new material to its fullest extent. This can slow down sustainability improvements in products. To counter this, it is suggested that the personal and non-rational side of decision-making is acknowledged and valued, that visions and ideology are used to encourage the introduction of new materials rather than relying on technical or economic aspects, and that designers and engineers are encouraged and enabled to take higher risks and evaluate more “unknown” parameters.To fully implement these suggestions, the following three things need to happen:A: Design and engineering education needs to teach students how to have more flexible mental models of materialsB: Industry should find ways for designers and engineers to experiment further and learn (both on an organizational and personal level)C: Academia should further investigate how behaviors, mental models and habits affect product development and design work, especially regarding material selection and material management.