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.

This thesis suggests the use of tools from the disciplines of Computational Linguistics and Knowledge Representation with the idea that such tools would enable the partial automation of two processes of Conceptual Design: the analysis of Requirements and the synthesis of concepts of solution. The viewpoint on Conceptual Design developed in this research is based on the systematic methodologies developed in the literature. The evolution of these methodologies provided precise description of the tasks to be achieved by the designing team in order to achieve successful design. Therefore, the argument of this thesis is that it is possible to create computer models of some of these tasks in order to partially automate the refinement of the design problem and the exploration of the design space. In Requirements Engineering, the definition of requirements consists in identifying the needs of various stakeholders and formalizing it into design speciႡcations. During this task, designers face the problem of having to deal with individuals from different expertise, expressing their needs with different levels of clarity. This research tackles this issue with requirements expressed in natural language (in this case in English). The analysis of needs is realised from different linguistic levels: lexical, syntactic and semantic. The lexical level deals with the meaning of words of a language. Syntactic analysis provides the construction of the sentence in language, i.e. the grammar of a language. The semantic level aims at Ⴁnding about the specific meaning of words in the context of a sentence. This research makes extensive use of a semantic atlas based on the concept of clique from graph theory. Such concept enables the computation of distances between a word and its synonyms. Additionally, a methodology and a metric of similarity was defined for clarifying requirements at syntactic, lexical and semantic levels. This methodology integrates tools from research collaborators. In the synthesis process, a Knowledge Representation of the necessary concepts for enabling computers to create concepts of solution was developed. Such, concepts are: function, input/output Ⴂow, generic organs, behaviour, components. The semantic atlas is also used at that stage to enable a mapping between functions and their solutions. It works as the interface between the concepts of this Knowledge Representation.

La implementació de la Directiva Europea 91/271/CEE referent a tractament d'aigües residuals urbanes va promoure la construcció de noves instal·lacions al mateix temps que la introducció de noves tecnologies per tractar nutrients en àrees designades com a sensibles. Tant el disseny d'aquestes noves infraestructures com el redisseny de les ja existents es va portar a terme a partir d'aproximacions basades fonamentalment en objectius econòmics degut a la necessitat d'acabar les obres en un període de temps relativament curt. Aquests estudis estaven basats en coneixement heurístic o correlacions numèriques provinents de models determinístics simplificats. Així doncs, moltes de les estacions depuradores d'aigües residuals (EDARs) resultants van estar caracteritzades per una manca de robustesa i flexibilitat, poca controlabilitat, amb freqüents problemes microbiològics de separació de sòlids en el decantador secundari, elevats costos d'operació i eliminació parcial de nutrients allunyant-les de l'òptim de funcionament. Molts d'aquestes problemes van sorgir degut a un disseny inadequat, de manera que la comunitat científica es va adonar de la importància de les etapes inicials de disseny conceptual. Precisament per aquesta raó, els mètodes tradicionals de disseny han d'evolucionar cap a sistemes d'avaluació mes complexos, que tinguin en compte múltiples objectius, assegurant així un millor funcionament de la planta. Tot i la importància del disseny conceptual tenint en compte múltiples objectius, encara hi ha un buit important en la literatura científica tractant aquest camp d'investigació. L'objectiu que persegueix aquesta tesi és el de desenvolupar un mètode de disseny conceptual d'EDARs considerant múltiples objectius, de manera que serveixi d'eina de suport a la presa de decisions al seleccionar la millor alternativa entre diferents opcions de disseny. Aquest treball de recerca contribueix amb un mètode de disseny modular i evolutiu que combina diferent tècniques com: el procés de decisió jeràrquic, anàlisi multicriteri, optimació preliminar multiobjectiu basada en anàlisi de sensibilitat, tècniques d'extracció de coneixement i mineria de dades, anàlisi multivariant i anàlisi d'incertesa a partir de simulacions de Monte Carlo. Això s'ha aconseguit subdividint el mètode de disseny desenvolupat en aquesta tesis en quatre blocs principals: (1) generació jeràrquica i anàlisi multicriteri d'alternatives, (2) anàlisi de decisions crítiques, (3) anàlisi multivariant i (4) anàlisi d'incertesa. El primer dels blocs combina un procés de decisió jeràrquic amb anàlisi multicriteri. El procés de decisió jeràrquic subdivideix el disseny conceptual en una sèrie de qüestions mes fàcilment analitzables i avaluables mentre que l'anàlisi multicriteri permet la consideració de diferent objectius al mateix temps. D'aquesta manera es redueix el nombre d'alternatives a avaluar i fa que el futur disseny i operació de la planta estigui influenciat per aspectes ambientals, econòmics, tècnics i legals. Finalment aquest bloc inclou una anàlisi de sensibilitat dels pesos que proporciona informació de com varien les diferents alternatives al mateix temps que canvia la importància relativa del objectius de disseny.El segon bloc engloba tècniques d'anàlisi de sensibilitat, optimització preliminar multiobjectiu i extracció de coneixement per donar suport al disseny conceptual d'EDAR, seleccionant la millor alternativa un cop s'han identificat decisions crítiques. Les decisions crítiques són aquelles en les que s'ha de seleccionar entre alternatives que compleixen de forma similar els objectius de disseny però amb diferents implicacions pel que respecte a la futura estructura i operació de la planta. Aquest tipus d'anàlisi proporciona una visió més àmplia de l'espai de disseny i permet identificar direccions desitjables (o indesitjables) cap on el procés de disseny pot derivar. El tercer bloc de la tesi proporciona l'anàlisi multivariant de les matrius multicriteri obtingudes durant l'avaluació de les alternatives de disseny. Específicament, les tècniques utilitzades en aquest treball de recerca engloben: 1) anàlisi de conglomerats, 2) anàlisi de components principals/anàlisi factorial i 3) anàlisi discriminant. Com a resultat és possible un millor accés a les dades per realitzar la selecció de les alternatives, proporcionant més informació per a una avaluació mes efectiva, i finalment incrementant el coneixement del procés d'avaluació de les alternatives de disseny generades. En el quart i últim bloc desenvolupat en aquesta tesi, les diferents alternatives de disseny són avaluades amb incertesa. L'objectiu d'aquest bloc és el d'estudiar el canvi en la presa de decisions quan una alternativa és avaluada incloent o no incertesa en els paràmetres dels models que descriuen el seu comportament. La incertesa en el paràmetres del model s'introdueix a partir de funcions de probabilitat. Desprès es porten a terme simulacions Monte Carlo, on d'aquestes distribucions se n'extrauen números aleatoris que es subsisteixen pels paràmetres del model i permeten estudiar com la incertesa es propaga a través del model. Així és possible analitzar la variació en l'acompliment global dels objectius de disseny per a cada una de les alternatives, quines són les contribucions en aquesta variació que hi tenen els aspectes ambientals, legals, econòmics i tècnics, i finalment el canvi en la selecció d'alternatives quan hi ha una variació de la importància relativa dels objectius de disseny. En comparació amb les aproximacions tradicionals de disseny, el mètode desenvolupat en aquesta tesi adreça problemes de disseny/redisseny tenint en compte múltiples objectius i múltiples criteris. Al mateix temps, el procés de presa de decisions mostra de forma objectiva, transparent i sistemàtica el perquè una alternativa és seleccionada en front de les altres, proporcionant l'opció que més bé acompleix els objectius marcats, mostrant els punts forts i febles, les principals correlacions entre objectius i alternatives, i finalment tenint en compte la possible incertesa inherent en els paràmetres del model que es fan servir durant les anàlisis. Les possibilitats del mètode desenvolupat es demostren en aquesta tesi a partir de diferents casos d'estudi: selecció del tipus d'eliminació biològica de nitrogen (cas d'estudi # 1), optimització d'una estratègia de control (cas d'estudi # 2), redisseny d'una planta per aconseguir eliminació simultània de carboni, nitrogen i fòsfor (cas d'estudi # 3) i finalment anàlisi d'estratègies control a nivell de planta (casos d'estudi # 4 i # 5). / The implementation of EU Directive 91/271/EEC concerning urban wastewater treatment promoted the construction of new facilities and the introduction of nutrient removal technologies in areas designated as sensitive. The need to build at a rapid pace imposed economically sound approaches for the design of the new infrastructures and the retrofit of the existing ones. These studies relied exclusively on the use of heuristic knowledge and numerical correlations generated from simplified activated sludge models. Hence, some of the resulting wastewater treatment plants (WWTPs) were characterized by a lack of robustness and flexibility, bad controller performance, frequent microbiology-related solids separation problems in the secondary settler, high operating and maintenance costs and/or partial nutrient removal, which made their performance far from optimal. Most of these problems arose because of inadequate design, making the scientific community aware of the crucial importance of the conceptual design stage. Thus, these traditional design approaches should turn into more complex assessment methods in order to conduct integrated assessments taking into account a multiplicity of objectives an hence ensuring a correct plant performance. Despite the importance of this fact only a few methods in the literature addressed the systematic evaluation of conceptual WWTP design alternatives using multiple objectives. Yet, the decisions made during this stage are of paramount importance in determining the future plant structure and operation. The main objective pursued in this thesis targets the development of a systematic conceptual design method for WWTP using multiple objectives, which supports decision making when selecting the most desirable option amongst several generated alternatives. This research work contributes with a modular and evolutionary approach combining techniques from different disciplines such as: a hierarchical decision approach, multicriteria decision analysis, preliminary multiobjective optimization using sensitivity functions, knowledge extraction and data mining techniques, multivariate statistical techniques and uncertainty analysis using Monte Carlo simulations. This is accomplished by dividing the design method into 4 different blocks: (1) hierarchical generation and multicriteria evaluation of the design alternatives, (2) analysis of critical decisions, (3) multivariate analysis and, finally, (4) uncertainty analysis. The first block of the proposed method, supports the conceptual design of WWTP combining a hierarchical decision approach with multicriteria analysis. The hierarchical decision approach breaks down the conceptual design into a number of issues that are easier to analyze and to evaluate while the multicriteria analysis allows the inclusion of different objectives at the same time. Hence, the number of alternatives to evaluate is reduced while the future WWTP design and operation is greatly influenced by environmental, technical, economical and legal aspects. Also, the inclusion of a sensitivity analysis facilitates the study of the variation of the generated alternatives with respect to the relative importance of the objectives. The second block, analysis of critical decisions, is tackled with sensitivity analysis, preliminary multiobjective optimization and knowledge extraction to assist the designer during the selection of the best alternative amongst the most promising alternatives i.e. options with a similar overall degree of satisfaction of the design objectives but with completely different implications for the future plant design and operation. The analysis provides a wider picture of the possible design space and allows the identification of desirable (or undesirable) WWTP design directions in advance.The third block of the proposed method, involves the application of multivariate statistical techniques to mine the complex multicriteria matrixes obtained during the evaluation of WWTP alternatives. Specifically, the techniques used in this research work are i) cluster analysis, ii) principal component/factor analysis, and iii) discriminant analysis. As a result, there is a significant improvement in the accessibility of the information needed for effective evaluation of WWTP alternatives, yielding more knowledge than the current evaluation methods to finally enhance the comprehension of the whole evaluation process. In the fourth and last block, uncertainty analysis of the different alternatives is further applied. The objective of this tool is to support the decision making when uncertainty on the model parameters used to carry out the analysis of the WWTP alternatives is either included or not. The uncertainty in the model parameters is introduced, i.e input uncertainty, characterising it by probability distributions. Next, Monte Carlo simulations are run to see how those input uncertainties are propagated through the model and affect the different outcomes. Thus, it is possible to study the variation of the overall degree of satisfaction of the design objectives, the contributions of the different objectives in the overall variance to finally analyze the influence of the relative importance of the design objectives during the selection of the alternatives. Thus, in comparison with the traditional approaches the conceptual design method developed in this thesis addresses design/redesign problems with respect to multiple objectives and multiple performance measures. Also, it includes a more reliable decision procedure that shows in a systematic, objective and transparent fashion the rationale way a certain alternative is selected and not the others. The decision procedure provides to the designer/decision maker with the alternative that best fulfils the defined objectives, showing its main advantages and weaknesses, the different correlations between the alternatives and evaluation criteria and dealing with the uncertainty prevailing in some of the model parameters used during the analysis. A number of case studies, selection of biological nitrogen removal process (case study #1), optimization of the setpoints in two control loops (case study #2), redesign to achieve simultaneous organic carbon, nitrogen and phosphorus removal (case study #3) and evaluation of control strategies at plant wide level (case studies #4 and #5), are used to demonstrate the capabilities of the conceptual design method.

THE THESIS FOCUSES ON A CONSTRUCTION DESIGN OF A NEW DRILLING HEAD DESIGNED TO REPLACE THE ORIGINAL ONE IN A MULTIDRILL HYNDAGA DRILLING RING. THE SUBSTITUTION IS SUPPOSED TO PROVIDE A SOLUTION TO THE SHORTCOMINGS OF THE CURRENTLY USED DRILLING HEAD. THE THESIS ANALYSES PARAMETERS OBTAINED FROM THE MANUFACTURER, NEW PRODUCTION REQUIREMENTS AND PROPOSES TWO TYPES OF MOTORS INNOVATIVE METHODS HAD BEEN IMPLEMENTED IN CALCULATIONS OF CONCEPTUAL PARAMETERS OF THE NECESSARY COMPONENTS. THE OUTCOME IS A NEW F-TYPE DRILLING HEAD.

Published works cite that 70-80% of the total cost of a product is established during conceptual design, and that improvements in time-to-market, quality, affordability, and global competitiveness require the development of better approaches to assist decision-making during the early stages of product design, as well as facilitate enterprise knowledge management and reuse. For many years, concurrent engineering and teaming have been viewed as “the answer” to product development woes, but studies reveal teaming is not sufficient to handle the task complexities of product development and the long-term goal of enterprise learning. The work of Roberto Verganti provides new insights with regard to reciprocal interdependencies (RIs), feedforward planning, selective anticipation in the context of improving teaming and concurrent engineering, as well as enterprise learning, knowledge management, reuse. In this research, reciprocal interdependencies management (RIM) is offered as a means of addressing product development and concurrent engineering issues occurring in the early stages of design. RIM is combination of Verganti’s concepts, a conceptual RIs structure, new RIM-application strategies, RIM-diagramming, and a conceptual RIM-based decisions support system, which come together to form a vision of a RIM-based enterprise knowledge management system. The conceptual RIM-based DSS is presented using the specific case of supporting a working-level integrated product team (IPT) engaged in the design of an aircraft bulkhead. A qualitative assessment tool is used to compare RIM to other approaches in the literature, and initial results are very favorable.

A gap exists in the methods used in industry and available in academia that prevents customers and engineers from having a voice when considering engineering risk appetite in the dynamic shaping of early-phase conceptual design trade study outcomes. Current methods used in Collaborative Design Centers either collect risk information after a conceptual design has been created, treat risk as an afterthought during the trade study process, or do not consider risk at all during the creation of conceptual designs. This dissertation proposes a risk-informed decision making framework that offers a new way to account for risk and make decisions based upon risk information within conceptual complex system design trade studies. A meaningful integration of the consideration of risk in trade studies is achieved in this framework thus elevating risk to the same level as other important system-level design parameters. Trade-offs based upon risk appetites of individuals are explicitly allowed under the framework, enabled by an engineering-specific psychometric risk survey that provides aspirational information to use in utility functions. This dissertation provides a novel framework and supporting methodologies for risk-informed design decisions and trades to be made that are based upon engineering risk appetites in conceptual design trade studies. / Graduation date: 2012

The thesis will discuss the Systems Engineering phase of an original Conceptual Design Engineering Methodology for Aerospace Engineering-Vehicle Synthesis. This iterative phase is shown to benefit from digitization of Integrated Product&Process Design (IPPD) activities, through the application of Product Lifecycle Management (PLM) technologies. Requirements analysis through the use of Quality Function Deployment (QFD) and 7 MaP tools is explored as an illustration. A "Requirements Data Manager" (RDM) is used to show the ability to reduce the time and cost to design for both new and legacy/derivative designs. Here the COTS tool Teamcenter Systems Engineering (TCSE) is used as the RDM. The utility of the new methodology is explored through consideration of a legacy RFP based vehicle design proposal and associated aerospace engineering. The 2001 American Helicopter Society (AHS) 18th Student Design Competition RFP is considered as a starting point for the Systems Engineering phase. A Conceptual Design Engineering activity was conducted in 2000/2001 by Graduate students (including the author) in Rotorcraft Engineering at the Daniel Guggenheim School of Aerospace Engineering at the Georgia Institute of Technology, Atlanta GA. This resulted in the "Kingfisher" vehicle design, an advanced search and rescue rotorcraft capable of performing the "Perfect Storm" mission, from the movie of the same name. The associated requirements, architectures, and work breakdown structure data sets for the Kingfisher are used to relate the capabilities of the proposed Integrated Digital Environment (IDE). The IDE is discussed as a repository for legacy knowledge capture, management, and design template creation. A primary thesis theme is to promote the automation of the up-front conceptual definition of complex systems, specifically aerospace vehicles, while anticipating downstream preliminary and full spectrum lifecycle design activities. The thesis forms a basis for additional discussions of PLM tool integration across the engineering, manufacturing, MRO and EOL lifecycle phases to support business management processes.