Sharing components in a product family requires a trade-off between the individual products' performances and overall family costs. It is critical for a successful family to identify which components are similar, so that sharing does not compromise the individual products' performances. This research formulates two commonality identification approaches for use in product family design and investigates their applicability in a generic product family design methodology. Having a commonality identification approach reduces the combinatorial sharing problem and allows for more quality family alternatives to be considered. The first is based on the pattern recognition technique of fuzzy c-means clustering in component subspaces. If components from different products are similar enough to be grouped into the same cluster, then those components could possibly become the same platform. Fuzzy equivalence relations that show the binary relationship from one products' component to a different products' component can be extracted from the cluster membership functions. The second approach builds a Bayesian network representing the joint distribution of a design space exploration. Using this model, a series of inferences can be made based on product performance and component constraints. Finally the posterior design variable distributions can be processed using a similarity metric like the earth mover distance to identify which products' components are similar to another's.

En adoptant un point de vue utilitariste du consommateur sur certains produits orientés service, nous avons d'abord contribué à la proposition d’un modèle de contextes d’usage que se doit de couvrir au mieux un produit. Le modèle conduit à une meilleure intégration des analyses de marketing et d’ingénierie de la conception amenant à une optimisation d'un produit paramétré plus orientée vers les besoins du marché ou à un meilleur étagement d'une famille de produits. Nous proposons une série d'indices qui révèlent l'adéquation entre les usages couverts par un produit de dimensions données ou une famille de produits donnée avec un espace d'usages cible qu’il s’agit de couvrir dans sa totalité ou en partie mais d'une manière suffisamment dominante par rapport à la concurrence. En premier lieu, l'indice de couverture d’usage (UCI) pour un produit unique est introduit par la cartographie du produit relativement à un ensemble d’utilisateurs représentatifs définis par des usages attendus. Sur cette base, l'UCI pour une famille de produits est construite pour évaluer la composition de la famille et la redondance des produits qui la composent. Les avantages par rapport à la traditionnelle estimation de la demande en marketing sont de réduire la complexité de l'enquête et de l'analyse des données et de pouvoir estimer le niveau de compétitivité d’une offre innovante sans nécessiter de retour d’expérience du marché. Nous expérimentons nos propositions sur un problème de reconception d’une famille de scies sauteuses. L'approche proposée permet d'évaluer l'adaptabilité, pour une famille de produits de tailles croissantes, à divers scénarios dans le contexte d'usage d'un marché cible. Les concepteurs peuvent s'appuyer sur les résultats pour éliminer les produits redondants au sein d'une famille. Des configurations de produits de tailles croissantes peuvent aussi être rapidement simulées et comparées de manière à aboutir à une famille minimale de produits idéalement étagée. / Adopting a utilitarian viewpoint of consumers on some service-oriented goods, we have first contributed to the proposal of a usage contexts model that a product should cover at most. The model leads to a higher integration of design engineering and marketing analyses which results in a more market-oriented optimization of a parameterized product or a better sampling of a product family. We propose a series of usage coverage indices that reveal the adequacy of a dimensioned product or a given product family to a targeted usage space to cover in its whole or for a part but sufficiently in a dominant way compared to competing products. First, the Usage Coverage Index (UCI) for single product is introduced by mapping the given product with a set of representative users defined by expected usages. On that basis, the UCI for a product family is constructed to evaluate the composition and redundancy of the family. The advantage compared to traditional demand estimation in marketing research is to reduce the complexity of survey and data analysis and to assess the competitiveness level of an innovative service offer without needing any return of experience from the market. We experiment our proposals on a jigsaw product family redesign problem. The proposed analysis approach helps to evaluate the adaptability, for a given scale-based product family, to diverse usage context scenarios in a target market. Designers can rely on the results to filter out redundant products within a family. Scale-based configurations of the products can also be rapidly simulated and compared to find out an appropriate sampled series of products.

Modular product architecture is characterized by the existence of standardized interfaces between the physical building blocks. A module is a collection of technical solutions that perform a function, with interfaces selected for company-specific strategic reasons. Approaches to modularity are the structured methods by which modular product architectures are derived. The approaches include Modular Function Deployment (MFD), Design Structure Matrix (DSM), Function Structure Heuristics and many other, including hybrids. The thesis includes a survey of relevant theory and a discussion of four challenges in product architecture research, detailed in the appended papers. One common experience from project work is structured methods such as DSM or MFD often do not yield fully conclusive results. This is usually because the algorithms used to generate modules do not have enough relevant data. Thus, we ask whether it is possible to introduce new data to make the output more conclusive. A case study is used to answer this question. The analysis indicates that with additional properties to capture product geometry, and flow of matter, energy, or information, the output is more conclusive. If product development projects even have an architecture definition phase, very little time is spent actually selecting the most suitable tool. Several academic models are available, but they use incompatible criteria, and do not capture experience-based or subjective criteria we may wish to include. The research question is whether we can define selection criteria objectively using academic models and experience-based criteria. The author gathers criteria from three academic models, adds experience criteria, performs a pairwise comparison of all available criteria and applies a hierarchical cluster analysis, with subsequent interpretation. The resulting evaluation model is tested on five approaches to modularity. Several conclusions are discussed. One is that of the five approaches studied, MFD and DSM have the most complementary sets of strengths and weaknesses, and that hybrids between these two fundamental approaches would be particularly interesting. The majority of all product development tries to improve existing products. A common criticism against all structured approaches to modularity is they work best for existing products. Is this perhaps a misconception? We ask whether MFD and DSM can be used on novel product types at an early phase of product development. MFD and DSM are applied to the hybrid drive train of a Forwarder. The output of the selected approaches is compared and reconciled, indicating that conclusions about a suitable modular architecture can be derived, even when many technical solutions are unknown. Among several conclusions, one is the electronic inverter must support several operating modes that depend on high-level properties of the drive train itself (such as whether regeneration is used). A modular structure for the electronic inverter is proposed. Module generation in MFD is usually done with Hierarchical Cluster Analysis (HCA), where the results are presented in the form of a Dendrogram. Statistical software can generate a Dendrogram in a matter of seconds. For DSM, the situation is different. Most available algorithms require a fair amount of processing time. One popular algorithm, the Idicula-Gutierrez-Thebeau Algorithm (IGTA), requires a total time of a few hours for a problem of medium complexity (about 60 components). The research question is whether IGTA can be improved to execute faster, while maintaining or improving quality of output. Two algorithmic changes together reduce execution time required by a factor of seven to eight in the trials, and improve quality of output by about 15 percent. / QC 20120605

According to production process theory, customization is directly related to cost and inversely related to volume, efficiency, and productivity. However, customers generally desire products that are individually tailored to their wants and needs. For this reason, as residential contractors grow, they struggle to meet customers' demands for flexibility. This struggle to increase customization is not unique to the construction industry and many other industries have studied this problem in depth. While the inverse relationship between customization and cost is generally true, mass customization can enable increased customization with limited or no increased cost. The residential construction process employs many mass customization enabling principles, including modularity and product family design. However, the preconstruction process fails to employ these same principles. The purpose of this study was to explore how mass customization principles can simplify customization in the residential preconstruction process. Two rounds of interviews were conducted with residential construction industry preconstruction experts. Using their input, a process for implementing mass customization was developed. The results demonstrate that implementing mass customization principles can greatly simplify the purchasing, estimating, and option pricing processes for residential contractors. However, mass customization also significantly affects company structure, cost control strategies, trade relationships, and leanness. This research is enlightening to residential contractors struggling to manage customization. It also provides direction for software developers targeting the residential construction processes.

La conception de variété (ou diversité) de produit est un processus essentiel pour atteindre le niveau de flexibilité requis par la personnalisation de masse. Pendant le processus de conception de la variété, les clients et les experts sont impliqués dans la définition de la meilleure solution. Par conséquent, la compréhension des liens entre les connaissances provenant de ces différents domaines, i.e. client, produit, processus est devenue nécessaire. Dans cette thèse, nous nous intéressons en particulier à la formalisation de ces connaissances. En effet, même si plusieurs efforts ont étés accomplis dans le domaine de la représentation de la connaissance, la pensée logiciste (i.e. utilisation de méthode à base de logiques formelles) reste la base de la majeure partie des travaux sur la formalisation de la connaissance. Des réflexions appropriées sur l’utilisation des logiques peuvent montrer les risques d’ambiguïté de la représentation: l’utilisation de la logique conduit souvent à une représentation sujette à plusieurs interprétations, i.e. une représentation ambiguë. Une représentation avec cette caractéristique ne répond pas à l’exigence de bien comprendre les liens entre les différentes connaissances impliquées dans la conception de la variété. Notre travail s’intéresse, donc, au développement d’un cadre de modélisation de la connaissance de conception basé sur l’anti-logicisme. Les travaux sur les systèmes développés à partir des principes de cette école de représentation de la connaissance montrent à travers des applications concrètes dans les domaines de la robotique ou des systèmes multi-agents que les comportements intelligents peuvent être obtenus sans une représentation de la connaissance basée sur les logiques. Ce cadre permet de développer une variété de produit-processus à partir d’une clientèle définie au départ. Finalement, un critère pour comparer les différentes alternatives de variété générées est aussi proposé. Une méthode pour instancier le cadre de modélisation sur un logiciel de CAO 3D a été développée. De plus, un prototype pour utiliser les modèles de connaissance avec un solveur mathématique a été conçu et développé. Les propositions ont été testées sur un cas d’étude industriel, i.e. batterie froide d’un appareil de réfrigération. Ce test a permis de discuter les avantages et les limites de nos propositions / The product variety design is an essential process in order to deal with the flexibility requested by the mass-customisation. During the product variety stage, customers and expert are involved in the definition of the best variety. Therefore a deep understanding of the links between knowledge coming from the customer domain, product domain and process domain is needed. In this thesis the research focus is on the formalisation of this knowledge. Indeed, even if many efforts are present in the knowledge representation literature, logics are always used to build these links. But appropriate reflections about the use of logics can lead to recognise the risk of ambiguity of the representations, i.e. more than one interpretation of the same represented object are possible. This ambiguity would make the represented knowledge not appropriate for the product variety design. In this work, we propose a framework for the knowledge representation based on the anti-logicism. Since the samples of anti-logicist systems (e.g. multi-agents, robots) have shown an intelligent behaviour without a representation based on logics, we use the principles the anti-logicism to propose our knowledge representation framework. A knowledge representation framework that allows to connect the customer requirements to the manufacturing process parameters is proposed. The core feature of the models based on this framework is the non-ambiguity. Indeed, each piece of knowledge that composes the model can be interpreted in one unique way. This feature allows the perfect collaboration between customer, product engineers and process engineering during the variety design stage. Once the pieces of knowledge coming from different domains are integrated in one model, the framework explains how to generate alternatives of product-process variety by starting from a given customer set. Finally a criterion to compare the different generated alternatives of product-process variety is proposed. A method to instantiate the framework on a 3D CAD has been developed. Moreover, a prototype that uses the knowledge model along with a mathematical solver to propose the best variety has been developed. The impact of the framework on the selection process and on the design process of a customisable product (i.e. water coil) is tested. The test of the instantiation and the prototype allows to show the advantages and the limit of the proposals

Researchers have paid relatively little attention to the fact that most design activities are actually more like redesign. These activities are characterized by an attempt to leverage experience, knowledge, and the capital that a company has already invested into existing engineering systems. In this dissertation, it is proposed that an approach be developed to aid designers in making decisions in redesign problems when there exist systems to be leveraged and multiple new systems to be created. In addition, strategy is introduced to the problem through the consideration that new systems may not be offered all at once, as is often assumed in product family design research. In this dissertation, the aim of the designer is assumed to be a creation, through redesign, of a series of new systems with desirable and distinct performance levels. In addition, a plan is required to involve as little redesign effort throughout the life of the family of systems as possible The proposed approach is based upon the concepts of Constructal Theory and previous work to create methods for the design of mass customized families of products. The existing methods are abstracted and heavily modified through the infusion of the compromise Decision Support Problems at all stages of the decision-making process. In addition, two indices are developed to represent considerations unique to redesign as opposed to original design. These indices for redesign effort and commonality value are utilized in the overall objective formulation for the approach. Through a thorough validation process and a large number of redesign scenarios, it is shown that the overall approach proposed can lead the designer towards promising redesign plans involving leveraging of existing systems, but that the constructal-inspired approach in and of itself has certain limitations when applied to redesign.

Many companies are using platform-based product designs to fulfill the requirements of customers while maintaining low cost. However, research that integrates sustainability into platform-based product design is still limited. Considering sustainability during platform-based design process is a challenge because the total life-cycle from pre-manufacturing, manufacturing and use to post-use stages as well as economic, environmental and societal performance in these stages must be considered. In this research, an approach for quantifying sustainability is introduced and a mathematical model is developed for identifying a more sustainable platform. Data from life-cycle assessment is used to quantify environmental factors; criteria from the Product Sustainability Index (ProdSI) are used to quantify societal factors. The Analytic Hierarchical Process method is used to assess relative importance of societal factors and the weighted sum method is used in the objective function for overall multi-objective optimization. A bicycle platform configuration will be used as a case study to demonstrate the application of the model. The relationship between commonality of the platform and sustainability performance is analyzed.

Le travail de thèse présenté dans ce mémoire porte sur des méthodes d'optimisation pour la conception conjointe des nomenclatures d'une famille de produits et de sa chaîne logistique. Dans les milieux industriels comme dans les services, le contexte commercial très concurrentiel oblige les entreprises à diversifier leurs offres pour mieux répondre aux demandes de leurs clients. La gestion de cette diversité est alors une problématique centrale : comment proposer une large variété de produits pour satisfaire les besoins des clients tout en maîtrisant les coûts de production, d'inventaire et de logistique ? Les réponses à ce problème relèvent des disciplines habituellement séparées : la conception des produits, la production et la logistique. Si une majorité des approches existantes traitent ces problématiques de façon séquentielle, l'interdisciplinarité apparaît cependant comme un élément essentiel dans la gestion de la diversité. L'objectif de cette thèse est de chercher comment améliorer les interactions entre la conception de familles de produits et l'optimisation des réseaux logistiques en proposant une étape de conception intermédiaire et en développant des outils mathématiques, avec un intérêt particulier porté aux problématiques de développement durable. / This PhD thesis addresses the problem of joint bills-of-materials and supply chain design for a product family. In industry as well as in services, the highly competitive business environment obliges companies to diversify their offers to meet the demands of their customers. Then, managing diversity is a central issue: how to offer a wide variety of products to meet customer needs while controlling costs of production, inventory and logistics? Answers to theses problems are usually in separate disciplines: product design, production and logistics. If most of existing approaches tackle these problems sequentially, interdisciplinarity, however, appears as a key aspect of diversity management. The objective of this thesis is to investigate how to improve the interaction between product families design and supply chain optimization and to develop mathematical tools, with a focus on sustainable development.

Les approches conventionnelles pour la génération de processus de fabrication sont inefficaces pour gérer la complexité induite par la variété des produits et la dynamique de fabrication. La génération des processus de fabrication reconfigurables (RPP) est une nouvelle méthode de CAPP qui vise à générer des processus de fabrication pour une famille de produits / pièces. Cette thèse vise à apporter une contribution majeure aux modèles de représentation et aux méthodes de génération permettant la génération des processus de fabrication reconfigurables à deux niveaux de granularité : famille de produits et famille de pièces. Les approches proposées pour le RPP sont compatibles avec une extension du concept de famille de produits / pièces qui est défini en utilisant le concept de domaine. Un modèle pour une variété fonctionnelle de produit / pièce basé sur des entités est développé afin de représenter les informations nécessaires à la gestion des processus reconfigurables en utilisant des techniques modulaires. Des modèles mathématiques et des modèles de représentation sont proposés pour décrire le processus de fabrication reconfigurable à deux niveaux de granularité. Sur la base des modèles de représentation, les méthodes de génération et les algorithmes sont ensuite détaillés dans ce cadre. En outre, un cadre global est proposé pour décrire comment les modèles et les méthodes proposés collaborent pour gérer la variété de produit / pièce et la dynamique de fabrication. Pour illustrer la faisabilité des modèles et méthodes proposés, deux familles de pompes (l’une à engrenage et l’autre à huile) sont utilisées à titre d'exemples illustratifs tout au long de ce mémoire de thèse. / Conventional manufacturing process planning approaches are inefficient to handle the process planning complexity induced by product variety and manufacturing dynamics. Reconfigurable process planning (RPP) is an emerging CAPP approach targeting to the generation of process plans for a product/part family. This thesis aims to give major contributions to the representation models and generation methods to support reconfigurable process planning at two granularity levels: product family and part family. The proposed approaches for RPP are compatible with an extended concept of product/part family which is defined by using the concept of “domain”. A feature-based product/part variety model is developed to represent the required information for RPP by using modular and platform-based techniques. Mathematical models and graph-based representation models are proposed to describe the reconfigurable process plan at two granularity levels. Based on the representation models, the generation methods and algorithms are then developed for RPP. In addition, a global framework is proposed to describe how the proposed RPP models and methods work together to handle the product/part variety and manufacturing dynamics. To test the feasibility of the proposed models and methods, a gear pump family and an oil pump body family are used as illustrative examples throughout this thesis.

This thesis covers a product development process carried out at the company “Asclepion Laser Technologies” for a product family of aesthetic medical laser devices. Due to different dimensions and dates of origin, an obvious divergence in the appearance of the present products within the product family had emerged in the company. Since the recognition value of a brand is greatly influenced by its product design the company aspired the development of a uniform design for the whole product family.   For this purpose, the objective of this thesis was the development of a new housing design. A modular design was pursued, to make it applicable for different devices of the same product family. Building multiple devices from the same housing modules reduces the overall production costs by decreasing tooling costs and decreasing the diversity of parts from suppliers. With the use of thermoforming as the predetermined production method, the production costs are kept low in addition.   During the master thesis project, the whole product development process was executed. The present thesis describes the development process in its four different phases, beginning with the pre-studies over ideation, concept development till the development of a final product ready for production. The implementation of suitable methods and tools in this design process, like observational studies and morphological idea generation, is outlined.   In collaboration with a thermoform specialist a CAD-model, ready for production, was delivered. After a revision of the developed product design by a commercial design company the design has been immediately transferred into serial production. / Denna uppsats beskriver den produktutvecklingsprocess som genomförts i samarbete med “Asclepion Laser Technologies” i syfte att ta fram ett gemensamt formspråk för en produktfamilj av medicinska lasrar. Eftersom att dessa produkter varierar i storlek såväl som utvecklingsår fanns stora skillnader i deras respektive formspråk. Eftersom att formspråk och design är viktiga för varumärkets identitet så eftersträvade företaget att införa ett gemensamt formspråk för sina produkter.   Examensarbetets syfte var sålunda att ta fram en design för nya kåpor. För att göra designen applicerbar över hela produktfamiljen så eftersträvades ett modulärt system. Genom att nyttja samma kåpor till flera produkter kan dessutom produktionskostnad, verktygskostnad och antal underleverantörer sänkas. Varmforming som preliminär tillverkningsmetod bidrar även det till en låg produktionskostnad.   Arbetet omfattade hela produktutvecklingsprocessen i fyra steg, med förstudie, idégenerering, konceptutveckling och produktionsklart koncept. Användandet av metoder och verktyg för utvecklingsprocessen, såsom observationsstudier morfologisk idégenerering, beskrivs övergripande.   I samarbete med en varmformningsspecialist levererades en produktionsklar CAD-modell. Efter att ha reviderats av ett kommersiellt designföretag har den framtagna designen satts i serieproduktion.