Indiana University-Purdue University Indianapolis (IUPUI) / This work is focused on developing viable self-healing coatings, especially considering the viability of the coating in a commercial context. With this in mind, finding low cost healing agents, with satisfactory healing and mechanical properties as well as adapting the healing system for use in coatings was required. Seven potential healing agents were evaluated and an air-drying triglyceride (linseed oil) was identified as the candidate healing agent. Different encapsulation techniques were evaluated and ureaformaldehyde microcapsules were chosen as the candidate encapsulation technique. Self-healing coatings were fabricated using urea-formaldehyde encapsulated linseed oil. EIS, SEM and TGA technologies were used to evaluate mechanical performance, corrosion resistance, and self-healing performance.

Designers often look for inspiration in their environment when exploring possible solutions to a given problem. However, many studies have reported that external stimuli may constrain designers’ imagination and limit their exploration to similar solutions, a phenomenon described as design fixation. Inspiration and fixation effects are traditionally studied with a similar experimental paradigm, which has produced a complex web of findings and explanations. Yet, when analysing the experiments and their findings closely, it becomes clear that there is considerable variation in how studies are conducted and the results they produce. Such variation makes it difficult to formulate a general view of how external stimuli affect the design process, and to translate the research findings into education and practice. Moreover, it raises questions about the reliability and effectiveness of the traditional experimental method. This thesis reports on a collection of studies that examine how design inspiration and fixation research is done and how it can be improved. It explores the research area by reviewing the literature and analysing data from a workshop; describes the research method by scrutinising experiments and their procedures; and explains the variation in research findings by testing experimental procedures empirically and suggesting new interpretations. My main findings are that: abstract stimuli can inspire or fixate designers to different degrees depending on how explicitly the stimuli are represented; external stimuli can inhibit the exploration of ideas that would otherwise be explored; the effect of experimental instructions varies depending on how encouraging the instructions are; and the way participants represent and elaborate ideas can moderate fixation results. Whilst this thesis offers insights into design practice and education, its main contribution is to design research, where it represents a fundamental material for those who are new to inspiration and fixation research, and for those who are already expert.

In this knowledge economy, organizations are leveraging their competence through the knowledge they possess. Managing knowledge will potentially retain the competence held by the organization if knowledge generated across its projects and units is captured, structured and reused. Even though many tools and techniques are proposed in the literature to support these activities, their adoption in industry has been meagre. This may be due to development of tools without basing them on substantial and careful descriptive studies. This raises the following research issues: the knowledge processes and knowledge sources available in organizations and their characteristics need to be understood better. To address these gaps, following objectives are addressed in this research: ♦ To understand the specific needs and capability of the organization for capture and reuse of product development knowledge and ♦ To evaluate various alternative supports for capture and structure of relevant, evolving product development knowledge for reuse. To address these objectives, two observational studies were conducted in the organizations. To get a broader picture about the knowledge processes occurring in the organization, a KRIT model is proposed which is an acronym for Knowledge of solutions-Requirements-Interactions-Tasks, in which interactions of the designers with people and tools play the central role in processing knowledge during design. The KRIT model is validated through the demonstration of the existence of its nodes and links. From the observations it has been found that interactions ‘designer working with computer’, ‘two designers working with a computer’ and ‘two designers interacting with each other’ are most frequently occurred, and occupied most of the time during designing. Any tools to support knowledge capture and reuse should support these interactions such that capture and reuse can be intuitive and in-built in a natural way into a designer’s work habits. It is emphasized that there is a substantial need to increase the percentage of time spent by designers on capturing knowledge during the design process. This increase in time would lead to decrease in a designers’ time spent on knowledge acquisition and dissemination provided designers are capturing reusable knowledge. To answer capture and reuse of knowledge in detail in the observational studies, a new taxonomy of knowledge is proposed. By linking the representations of argumentation, designer’s activities, and the artefact being designed, we argued that the expressiveness of this taxonomy is high compared to the others proposed in the literature. The taxonomy has three broad categories of knowledge: topics, classes, and activities. Based on the definitions of the factors used in the taxonomy and the analysis of the protocols, the factors in each group under each category are argued to be mutually exclusive. In order to study the links between the proposed categories and factors in the taxonomy of knowledge, a method for converting the questions and answers (from the protocol data) into a generic format is framed. The taxonomy is validated comprehensively, and is able to cover various stages of design. Most of the designers’ time was spent working with a CAD package, in which most of the kinds of knowledge mentioned in the proposed taxonomy of knowledge was neither captured not reused. The important observations noted by comparing the knowledge captured in the preliminary study and the main study are as follows: Compared to the preliminary study, process related information and knowledge are captured higher in the main study. In the main study behavioural related content is captured more; whereas in the preliminary study structural content is captured more. The factors organization, usage, maintenance and sales captured in the preliminary study are not at all captured in the main study. In order to assess the usefulness of the knowledge captured, the kinds of knowledge needs of designers were compared with the kinds of knowledge captured. The important observations about the knowledge needs are: Irrespective of the design stages, in almost 50% of the questions, designers interacted with others to know about old issues or proposals in both the studies. A designer’s time for designing would benefit considerably if the answers for these 50% of the old questions were captured and made available for retrieval in formal documents. In both the studies, proposals based questions played a vital role in the questions analyzed. It shows that considerable proportion of time was spent by the designers on validating, by asking questions, the answers known to them. In contrast to the preliminary study, the designers’ needs for process-related information or knowledge were much higher than that for product-related information or knowledge. Comparing the generic questions obtained from the knowledge needs and knowledge captured reveals that only 14% and 26% with product related content and only 10% and 11.3% of the process based content asked by designers during designing were captured in the preliminary and the main study. These results show that there is a mismatch between knowledge captured and knowledge needed by the designers. This may be one of the primary reasons for the poor usage of documents in the organization. The generic questions generated from the questions asked by the designers and various documents will act as a guideline to the designers for what knowledge and information should and should not to be captured. Due to restrictions in the observations, a questionnaire survey was conducted to achieve the objective to collect 10% of total number of employees’ perspectives about the issues considered in this research. The important observations from the analyses of the collected questionnaire are: Designers’ perceive all types of interactions as important and frequent for information generation and sharing. These results are contradictory to the personal observations in which only interactions ‘designer working with computer’ and ‘two designers working with a computer’ occurred frequently. This shows that designers are unable to identify the kinds of interaction which they perform in their daily activities. Due to this, the information processes occurring within these interactions are not perceptible to the designers. Designers perceive that they get the right information at the right time in only 4 or more out of 10 for most of the times. This perception illustrates there is substantial need for the development of support to satisfy the information needs of designers. Analyses of the types of questions reveal that the question asking behavior of the designers is not static; the major share of questions falling under the category ‘question from answer given’ could be interpreted as: designers often do not frame exact questions to fulfil their requirements; they grab the opportunity to take as much as knowledge as possible during an interaction. Analyses of the types of answers reveal that designers gave more inferences on their answers in order to give a better response, which in turn should help reduce the number of questions subsequently asked especially in the protocol coded as ‘new answer’. Two studies have been used to assess the effectiveness of seven tools for supporting knowledge capture and reuse. The important observations from the initial study are: Mobile E-Notes TakerTM is ranked higher because this equipment provides a blend of properties between the paper and computer. These observations stress the importance of features provided for knowledge generation, modification, capture and reuse in the system. The observations from analyzing the three top rated tools (Mobile E-Notes TakerTM, Tablet with viewing facility and Computer with RhinocerosTM CAD package) to understand influence of these tools on knowledge capture and reuse during conceptual designing are: The differences observed in the percentage of capture between the usage of the three tools demonstrate that tools have an influence on the knowledge capture activity. Even though none of the three tools capture adequate knowledge during designing, Mobile e-Notes TakerTM seems to be the best tool for capture compared to the other two tools, both in the original and redesign experiments. These results suggest that some other mechanisms should be added to these tools so that their effectiveness of capturing could be increased. One mechanism is to incorporate the proposed KRIT model and the taxonomy of knowledge during designing. This integration will be one of the good mechanisms to aid knowledge capture and reuse, because the knowledge capture will occur along with the knowledge creation process. We believe that through this integration the purpose to enhance the knowledge capture and reuse during the design process will be achieved.