Managing organisational knowledge is crucial to increase business performance and competitiveness. However, given the complexity and dynamic nature of knowledge management practices, multinational organisations experience difficulties in identifying business opportunities and often fail to make necessary investments. This thesis develops an alternative perspective on knowledge management through the creation of a model based on socio-technical characteristics and organisational ignorance, and argues that managing nescience, i.e. knowing what needs to be known and also acknowledging the power of understanding the unknown, could facilitate employees' knowledge sharing behaviour and could improve both short-term opportunistic value capture and longer term business sustainability. It also creates a novel technique for managing dysfunctional knowledge management scenarios and improving knowledge management practices in the workplace by definition of the concept of KM anti-patterns, while discussing practices that reduce the risk of making the wrong decision when using uncertain information. The philosophy of this study is based on an interpretative approach with inductive reasoning. Both qualitative and quantitative methods, based mainly on workshop style discussions, questionnaires and semi-structured interview data, were implemented using various departments of one multinational organisation within the Aerospace and Defence industry as units of the analysis. Managing organisational ignorance is seldom and insufficiently discussed by the current KM literature and no previous attempt has been made to detect, analyse and categorise KM dysfunctional situations using a systematic KM anti-pattern template. It is argued that the issues addressed in this study could lead to inefficient or otherwise inappropriate KM practices; therefore it is important, particularly for managers and senior executives, to acknowledge, verify and act upon such matters in order to increase performance within their business, and optimise the level of knowledge for an individual employee or group in knowledge intensive settings.

Les expériences bioinformatiques sont généralement effectuées à l'aide de workflows scientifiques dans lesquels les tâches sont enchaînées les unes aux autres pour former des structures de graphes très complexes et imbriquées. Les systèmes de workflows scientifiques ont ensuite été développés pour guider les utilisateurs dans la conception et l'exécution de workflows. Un avantage de ces systèmes par rapport aux approches traditionnelles est leur capacité à mémoriser automatiquement la provenance (ou lignage) des produits de données intermédiaires et finaux générés au cours de l'exécution du workflow. La provenance d'un produit de données contient des informations sur la façon dont le produit est dérivé, et est cruciale pour permettre aux scientifiques de comprendre, reproduire, et vérifier les résultats scientifiques facilement. Pour plusieurs raisons, la complexité du workflow et des structures d'exécution du workflow est en augmentation au fil du temps, ce qui a un impact évident sur la réutilisation des workflows scientifiques.L'objectif global de cette thèse est d'améliorer la réutilisation des workflows en fournissant des stratégies visant à réduire la complexité des structures de workflow tout en préservant la provenance. Deux stratégies sont introduites. Tout d'abord, nous proposons une approche de réécriture de la structure du graphe de n'importe quel workflow scientifique (classiquement représentée comme un graphe acyclique orienté (DAG)) dans une structure plus simple, à savoir une structure série-parallèle (SP) tout en préservant la provenance. Les SP-graphes sont simples et bien structurés, ce qui permet de mieux distinguer les principales étapes du workflow. En outre, d'un point de vue plus formel, on peut utiliser des algorithmes polynomiaux pour effectuer des opérations complexes fondées sur les graphiques (par exemple, la comparaison de workflows, ce qui est directement lié au problème d’homomorphisme de sous-graphes) lorsque les workflows ont des SP-structures alors que ces opérations sont reliées à des problèmes NP-hard pour des graphes qui sont des DAG sans aucune restriction sur leur structure. Nous avons introduit la notion de préservation de la provenance, conçu l’algorithme de réécriture SPFlow et réalisé l’outil associé.Deuxièmement, nous proposons une méthodologie avec une technique capable de réduire la redondance présente dans les workflow (en supprimant les occurrences inutiles de tâches). Plus précisément, nous détectons des « anti-modèles », un terme largement utilisé dans le domaine de la conception de programme, pour indiquer l'utilisation de formes idiomatiques qui mènent à une conception trop compliquée, et qui doit donc être évitée. Nous avons ainsi conçu l'algorithme DistillFlow qui est capable de transformer un workflow donné en un workflow sémantiquement équivalent «distillé», c’est-à-dire, qui est libre ou partiellement libre des anti-modèles et possède une structure plus concise et plus simple. Les deux principales approches de cette thèse (à savoir, SPFlow et DistillFlow) sont basées sur un modèle de provenance que nous avons introduit pour représenter la structure de la provenance des exécutions du workflowl. La notion de «provenance-équivalence» qui détermine si deux workflows ont la même signification est également au centre de notre travail. Nos solutions ont été testées systématiquement sur de grandes collections de workflows réels, en particulier avec le système Taverna. Nos outils sont disponibles à l'adresse: https://www.lri.fr/~chenj/. / Bioinformatics experiments are usually performed using scientific workflows in which tasks are chained together forming very intricate and nested graph structures. Scientific workflow systems have then been developed to guide users in the design and execution of workflows. An advantage of these systems over traditional approaches is their ability to automatically record the provenance (or lineage) of intermediate and final data products generated during workflow execution. The provenance of a data product contains information about how the product was derived, and it is crucial for enabling scientists to easily understand, reproduce, and verify scientific results. For several reasons, the complexity of workflow and workflow execution structures is increasing over time, which has a clear impact on scientific workflows reuse.The global aim of this thesis is to enhance workflow reuse by providing strategies to reduce the complexity of workflow structures while preserving provenance. Two strategies are introduced.First, we propose an approach to rewrite the graph structure of any scientific workflow (classically represented as a directed acyclic graph (DAG)) into a simpler structure, namely, a series-parallel (SP) structure while preserving provenance. SP-graphs are simple and layered, making the main phases of workflow easier to distinguish. Additionally, from a more formal point of view, polynomial-time algorithms for performing complex graph-based operations (e.g., comparing workflows, which is directly related to the problem of subgraph homomorphism) can be designed when workflows have SP-structures while such operations are related to an NP-hard problem for DAG structures without any restriction on their structures. The SPFlow rewriting and provenance-preserving algorithm and its associated tool are thus introduced.Second, we provide a methodology together with a technique able to reduce the redundancy present in workflows (by removing unnecessary occurrences of tasks). More precisely, we detect "anti-patterns", a term broadly used in program design to indicate the use of idiomatic forms that lead to over-complicated design, and which should therefore be avoided. We thus provide the DistillFlow algorithm able to transform a workflow into a distilled semantically-equivalent workflow, which is free or partly free of anti-patterns and has a more concise and simpler structure.The two main approaches of this thesis (namely, SPFlow and DistillFlow) are based on a provenance model that we have introduced to represent the provenance structure of the workflow executions. The notion of provenance-equivalence which determines whether two workflows have the same meaning is also at the center of our work. Our solutions have been systematically tested on large collections of real workflows, especially from the Taverna system. Our approaches are available for use at https://www.lri.fr/~chenj/.

As metodologias ágeis e em especial a Programação eXtrema (XP) surgem como um contraponto aos métodos tradicionais de desenvolvimento de software. Nos encontramos em um momento no qual considera-se aceitável encontrar defeitos em programas de computador, até mesmo naqueles sistemas pelos quais temos que pagar muito dinheiro. Melhorar o ensino de técnicas para que equipes possam colaborar no desenvolvimento de software de qualidade é essencial para que esta área do conhecimento alcance a maturidade que esperamos. O ensino de XP é uma tarefa relativamente complexa pois exige que pessoas passem por uma mudança cultural, para aceitar seus valores, princípios e práticas. Diferentes organizações precisam adaptar a metodologia para que ela funcione bem em seu contexto local. Encontrar maneiras de facilitar o ensino e a adoção das práticas ágeis é fundamental para melhorar a qualidade do software desenvolvido no país. Este trabalho pesquisa o ensino de XP em contextos acadêmicos, governamentais e industriais. Três estudos de caso foram conduzidos e analisados para sugerir padrões que podem auxiliar o ensino da metodologia por um educador em qualquer contexto. / Agile methodologies, specially eXtreme Programming (XP), appear as a counterpoint to traditional software development methods. We live in a moment were it is considered acceptable to find bugs in computer programs, even those for which we pay a lot of money. It is essential to improve the way we teach techniques with which teams can collaborate on the development of quality software so that this area of knowledge reaches the maturity we wish. Teaching XP is a relatively complex task because it implies that people must go through a cultural change to accept its values, principles, and practices. Different organizations need to adapt the methodology so that it will work well in their local context. Finding ways to facilitate teaching and adopting agile practices is fundamental to improve the quality of software being developed in the country. This work researches the process of teaching XP in academic, governmental and industrial con- texts. Three case studies were conducted and analyzed so that we could suggest patterns that can support educators teaching the methodology in any context.

As metodologias ágeis e em especial a Programação eXtrema (XP) surgem como um contraponto aos métodos tradicionais de desenvolvimento de software. Nos encontramos em um momento no qual considera-se aceitável encontrar defeitos em programas de computador, até mesmo naqueles sistemas pelos quais temos que pagar muito dinheiro. Melhorar o ensino de técnicas para que equipes possam colaborar no desenvolvimento de software de qualidade é essencial para que esta área do conhecimento alcance a maturidade que esperamos. O ensino de XP é uma tarefa relativamente complexa pois exige que pessoas passem por uma mudança cultural, para aceitar seus valores, princípios e práticas. Diferentes organizações precisam adaptar a metodologia para que ela funcione bem em seu contexto local. Encontrar maneiras de facilitar o ensino e a adoção das práticas ágeis é fundamental para melhorar a qualidade do software desenvolvido no país. Este trabalho pesquisa o ensino de XP em contextos acadêmicos, governamentais e industriais. Três estudos de caso foram conduzidos e analisados para sugerir padrões que podem auxiliar o ensino da metodologia por um educador em qualquer contexto. / Agile methodologies, specially eXtreme Programming (XP), appear as a counterpoint to traditional software development methods. We live in a moment were it is considered acceptable to find bugs in computer programs, even those for which we pay a lot of money. It is essential to improve the way we teach techniques with which teams can collaborate on the development of quality software so that this area of knowledge reaches the maturity we wish. Teaching XP is a relatively complex task because it implies that people must go through a cultural change to accept its values, principles, and practices. Different organizations need to adapt the methodology so that it will work well in their local context. Finding ways to facilitate teaching and adopting agile practices is fundamental to improve the quality of software being developed in the country. This work researches the process of teaching XP in academic, governmental and industrial con- texts. Three case studies were conducted and analyzed so that we could suggest patterns that can support educators teaching the methodology in any context.

Les logiciels sont en constante évolution, nécessitant une maintenance et un développement continus. Ils subissent des changements tout au long de leur vie, que ce soit pendant l'ajout de nouvelles fonctionnalités ou la correction de bogues. Lorsque les logiciels évoluent, leurs architectures ont tendance à se dégrader et deviennent moins adaptables aux nouvelles spécifications des utilisateurs. En effet, les architectures de ces logiciels deviennent plus complexes et plus difficiles à maintenir à cause des nombreuses dépendances entre les artefacts. Par conséquent, les développeurs doivent comprendre les dépendances entre les artefacts des logiciels pour prendre des mesures proactives qui facilitent les futurs changements et ralentissent la dégradation des architectures des logiciels. D'une part, le maintien d'un logiciel sans la compréhension des les dépendances entre ses artefacts peut conduire à l'introduction de défauts. D'autre part, lorsque les développeurs manquent de connaissances sur l'impact de leurs activités de maintenance, ils peuvent introduire des défauts de conception, qui ont un impact négatif sur l'évolution du logiciel. Ainsi, les développeurs ont besoin de mécanismes pour comprendre comment le changement d'un artefact impacte le reste du logiciel. Dans cette thèse, nous proposons trois contributions principales : La spécification de deux nouveaux patrons de changement et leurs utilisations pour fournir aux développeurs des informations utiles concernant les dépendances de co-changement. La spécification de la relation entre les patrons d'évolutions des artefacts et les fautes. La découverte de la relation entre les dépendances des anti-patrons et la prédisposition des différentes composantes d'un logiciel aux fautes. / Program maintenance accounts for the largest part of the costs of any program. During maintenance activities, developers implement changes (sometimes simultaneously) on artefacts to fix bugs and to implement new requirements. Thus, developers need knowledge to identify hidden dependencies among programs artefacts and detect correlated artefacts. As programs evolved, their designs become more complex over time and harder to change. In the absence of the necessary knowledge on artefacts dependencies, developers could introduce design defects and faults that causes development and maintenance costs to rise. Therefore, developers must understand the dependencies among program artefacts and take proactive steps to facilitate future changes and minimize fault proneness. On the one hand, maintaining a program without understanding the different dependencies between their artefacts may lead to the introduction of faults. On the other hand, when developers lack knowledge about the impact of their maintenance activities, they may introduce design defects, which have a negative impact on program evolution. Thus, developers need mechanisms to understand how a change to an artefact will impact the rest of the programs artefacts and tools to detect design defects impact. In this thesis, we propose three principal contributions. The first contribution is two novel change patterns to model new co-change and change propagation scenarios. We introduce the Asynchrony change pattern, corresponding to macro co-changes, i.e., of files that co-change within a large time interval (change periods), and the Dephase change pattern, corresponding to dephase macro co-changes, i.e., macro co-changes that always happen with the same shifts in time. We present our approach, named Macocha, and we show that such new change patterns provide interesting information to developers. The second contribution is proposing a novel approach to analyse the evolution of different classes in object-oriented programs and to link different evolution behaviour to faults. In particular, we define an evolution model for each class to study the evolution and the co-evolution dependencies among classes and to relate such dependencies with fault-proneness. The third contribution concerns design defect dependencies impact. We propose a study to mine the link between design defect dependencies, such as co-change dependencies and static relationships, and fault proneness. We found that the negative impact of design defects propagate through their dependencies. The three contributions are evaluated on open-source programs.

Les logiciels sont en constante évolution, nécessitant une maintenance et un développement continus. Ils subissent des changements tout au long de leur vie, que ce soit pendant l'ajout de nouvelles fonctionnalités ou la correction de bogues. Lorsque les logiciels évoluent, leurs architectures ont tendance à se dégrader et deviennent moins adaptables aux nouvelles spécifications des utilisateurs. En effet, les architectures de ces logiciels deviennent plus complexes et plus difficiles à maintenir à cause des nombreuses dépendances entre les artefacts. Par conséquent, les développeurs doivent comprendre les dépendances entre les artefacts des logiciels pour prendre des mesures proactives qui facilitent les futurs changements et ralentissent la dégradation des architectures des logiciels. D'une part, le maintien d'un logiciel sans la compréhension des les dépendances entre ses artefacts peut conduire à l'introduction de défauts. D'autre part, lorsque les développeurs manquent de connaissances sur l'impact de leurs activités de maintenance, ils peuvent introduire des défauts de conception, qui ont un impact négatif sur l'évolution du logiciel. Ainsi, les développeurs ont besoin de mécanismes pour comprendre comment le changement d'un artefact impacte le reste du logiciel. Dans cette thèse, nous proposons trois contributions principales : La spécification de deux nouveaux patrons de changement et leurs utilisations pour fournir aux développeurs des informations utiles concernant les dépendances de co-changement. La spécification de la relation entre les patrons d'évolutions des artefacts et les fautes. La découverte de la relation entre les dépendances des anti-patrons et la prédisposition des différentes composantes d'un logiciel aux fautes. / Program maintenance accounts for the largest part of the costs of any program. During maintenance activities, developers implement changes (sometimes simultaneously) on artefacts to fix bugs and to implement new requirements. Thus, developers need knowledge to identify hidden dependencies among programs artefacts and detect correlated artefacts. As programs evolved, their designs become more complex over time and harder to change. In the absence of the necessary knowledge on artefacts dependencies, developers could introduce design defects and faults that causes development and maintenance costs to rise. Therefore, developers must understand the dependencies among program artefacts and take proactive steps to facilitate future changes and minimize fault proneness. On the one hand, maintaining a program without understanding the different dependencies between their artefacts may lead to the introduction of faults. On the other hand, when developers lack knowledge about the impact of their maintenance activities, they may introduce design defects, which have a negative impact on program evolution. Thus, developers need mechanisms to understand how a change to an artefact will impact the rest of the programs artefacts and tools to detect design defects impact. In this thesis, we propose three principal contributions. The first contribution is two novel change patterns to model new co-change and change propagation scenarios. We introduce the Asynchrony change pattern, corresponding to macro co-changes, i.e., of files that co-change within a large time interval (change periods), and the Dephase change pattern, corresponding to dephase macro co-changes, i.e., macro co-changes that always happen with the same shifts in time. We present our approach, named Macocha, and we show that such new change patterns provide interesting information to developers. The second contribution is proposing a novel approach to analyse the evolution of different classes in object-oriented programs and to link different evolution behaviour to faults. In particular, we define an evolution model for each class to study the evolution and the co-evolution dependencies among classes and to relate such dependencies with fault-proneness. The third contribution concerns design defect dependencies impact. We propose a study to mine the link between design defect dependencies, such as co-change dependencies and static relationships, and fault proneness. We found that the negative impact of design defects propagate through their dependencies. The three contributions are evaluated on open-source programs.