A Method for Defining IEEE Std 1471 viewpoints

With the growing impact of information technology the proper understanding of IT-architecture designs is becoming ever more important. Much debate has been going on about how to describe them. In 2000, the IEEE Std 1471 proposed a model of an architecture description and its context. In this paper we propose a lightweight method for modeling architectural information after (part of) the conceptual model of IEEE Std 1471 and defining IEEE Std 1471 viewpoints. The method gives support by outlining in textual form and in diagram form the relation of the concerns of the stakeholders to the architectural information. The definition of viewpoints can then be done with insight from these relations. The method has four steps: (1) creating stakeholder profiles, (2) summarizing internal design documentation, (3) relating the summary to the concerns of the stakeholders, and (4) defining viewpoints. We have conducted a round of discussion and testing in practice in various settings. In this paper we present the feedback we received and propose improvements. © 2005 Elsevier Inc. All rights reserved

A Method For Defining IEEE Std 1471 Viewpoints

With the growing impact of information technology the proper understanding of IT-architecture designs is becoming ever more important. Much debate has been going on about how to describe them. In 2000, the IEEE Std 1471 proposed a model of an architecture description and its context. In this paper we propose a lightweight method for modeling architectural information after (part of) the conceptual model of IEEE St

An interpretive case study into the application of software engineering theory

Even before software engineering was formally defined as a discipline, software projects were notorious for being behind schedule and over budget. The resulting software systems were also often described as unreliable. Researchers in the field have, over the years, theorised and proposed many standards, methods, processes and techniques to improve software project outcomes. Based on allegorical evidence, however, it would seem that these proposals are often not applied in practice. This study was inspired by a desire to probe this general theme, namely of the extent to which (if at all) software engineering theory is adopted in practice. The core of this research is an interpretive case study of a software project in the financial services industry that ran from end 2006 to mid 2008. I was one of a team of approximately 20 developers, analysts and development managers working on the project, until I left the company in 2009. Results are reported in a two-phase fashion over several themes. Firstly, the literature of recommended software engineering practices relating to a particular theme is reviewed. This is regarded as the "theory". Thereafter, the observations and evidence collected from the interpretive study in regard to the relevant theme is presented and discussed. The first theme investigated is the notion of "project outcome". Definitions of successful and failed software projects are considered from the perspective of the various stakeholders. Also considered are factors that contribute to project success or failure. After examining how case study participants viewed the project’s outcome, it is argued that the project could neither be labelled as a complete success nor as a complete failure. Two areas were identified as problematic: the requirements gathering process; and the system architecture that had been chosen. Improvements in these areas would arguably have most benefitted the project’s outcome. For this reason, recommended practices were probed in the literature relating both to requirements engineering and also to software architecture design. The case study project was then evaluated against these recommended practices to determine the degree to which they were implemented. In cases where the recommended practices were not implemented or only partially implemented, a number of reasons for the lack of adoption are considered. Of course, the conclusions made in this study as to why the recommended practices were not implemented cannot be naïvely generalized to the software engineering field as a whole. Instead, in line with the interpretive nature of the study, an attempt was made to gain in depth knowledge of a particular project, to show how that project’s individual characteristics influenced the adoption of software engineering theory, and to probe the consequences of such adoption or lack thereof. The study suggested that the complex and individual nature of software projects will have a substantial influence on the extent to which theory is adopted in practice. It also suggested that the impact such adoption will have on a project’s outcome will be critically influenced by the nature of the software project. CopyrightDissertation (MSc)--University of Pretoria, 2012.Computer Scienceunrestricte

Mise en correspondance et gestion de la cohérence de modèles hétérogènes évolutifs

To understand and manipulate a complex system, it is necessary to apply the separation of concerns and produce separate parts. In Model Driven Engineering (MDE), these parts are represented by models qualified as partial models. In this context of multi-modeling, these models are called heterogeneous when they are described in separate modeling languages dedicated to different business domains: DSML (Domain Specific Modeling Language). Global model creation requires identifying existing correspondences between the elements of the partial models. However, in practice these correspondences are either incompletely identified or not sufficiently formalized to be maintained when the partial models evolve. This restricts their use and does not allow to fully exploit them for building the global model or for treating partial models evolution. The contribution of this thesis is twofold. The first contribution deals with a process for creating a global view of the system by means of a composition based on partial models matching. Identified correspondences between models elements are based on types of relationship instantiated from a metamodel of correspondences. This latter is extensible, depending on the considered application domain, and allows supporting the concepts related to this domain. Correspondences are firstly identified between meta-elements belonging to metamodels of the respective partial models. Correspondences between model elements are then obtained by a refinement mechanism, supported by an ad hoc Semantic Expression language: SED (Semantic Expression DSL). The composition is called “virtual” since elements represented in a correspondence are only references to elements belonging to partial models. Therefore, models interconnected by this correspondences form a virtual global model. The second contribution relates the consistency of the global model. Indeed, as models evolve over time, changing one or several elements involved in a correspondence, may cause the inconsistency of the global model. To maintain its consistency, we propose a second process enabling to automatically identify the changes, classify them and treat their impacts on the involved model elements. Management of repercussions is performed semi-automatically by the expert by means of strategies and weights. This work has been implemented through a support tool named HMCS (Heterogeneous Matching and Consistency management Suite) based on the Eclipse Platform. The approach has been validated and illustrated through a case study related to the management of a Hospital Emergency Service. This work was led in collaboration with the “CHU of Montpellier”.Pour permettre la compréhension et la manipulation d’un système complexe, le découpage en parties séparées est nécessaire. En Ingénierie Dirigée par les Modèles (ou Model Driven Engineering), ces parties sont représentées par des modèles, que nous qualifions de modèles partiels, dans la mesure où ils sont focalisés sur des domaines métiers distincts. Dans ce contexte de multi-modélisation, ces modèles sont dits hétérogènes quand ils sont décrits dans des langages de modélisation distincts dédiés à différents domaines métiers : DSML (Domain Specific Modeling language). La compréhension et l’exploitation efficace des connaissances relatives à un tel système supposent la construction d’un modèle global représentant son fonctionnement. La création du modèle global requiert l’identification des correspondances existant entre les éléments des différents modèles partiels. Dans la pratique, ces correspondances sont soit incomplètement identifiées, soit insuffisamment formalisées pour être maintenues lorsque les modèles partiels évoluent. Ceci limite leur utilisation et ne permet pas de les exploiter pleinement lors de la construction du modèle global ou du traitement de l’évolution des modèles partiels. L’apport de cette thèse est double. La première contribution est celle d’un processus permettant la création d’une vue globale du système par l’intermédiaire d’une composition fondée sur la mise en correspondance des modèles partiels. Les correspondances identifiées entres les éléments des modèles se basent sur des types de relations instanciées à partir d’un métamodèle de correspondance. Ce dernier est extensible (selon les spécificités du domaine d’application considéré) et permet de supporter les concepts relatifs à ce domaine. Les correspondances sont d’abord identifiées entre les méta-éléments des métamodèles respectifs des modèles partiels. Les correspondances entre les éléments de modèles sont ensuite obtenues par un mécanisme de raffinement, supporté par un langage d’expression sémantique ad hoc : SED (Semantic Expression DSL). La composition est dite « virtuelle » dans la mesure où les éléments figurant dans une correspondance ne sont que des références aux éléments appartenant aux modèles partiels. De ce fait, les modèles interconnectés par ces correspondances forment un modèle global virtuel. La seconde contribution est relative au maintien de la cohérence des modèles partiels et du modèle global. En effet, les modèles évoluant dans le temps, le changement d’un élément ou de plusieurs éléments participant à l’expression des correspondances, peut entrainer l’incohérence du modèle global. Pour maintenir la cohérence du modèle global, nous proposons un second processus permettant tout d’abord d’identifier automatiquement les changements réalisés ainsi que leurs classifications et leurs répercussions sur les éléments de modèles concernés. Par la suite, les différents cycles sont gérés à l’aide de l’expert puis une liste de changements est générée en fonction de la stratégie choisie et des coefficients de pondération. Enfin, le traitement des changements est réalisé de façon semi-automatique. Ce travail a été concrétisé par le développement d’un outil support nommé HMCS (Heterogeneous Matching and Consistency management Suite), basé sur la plateforme Eclipse. L’approche a été validée et illustrée à travers un cas d’étude portant sur la gestion du Service d'Urgence d'un hôpital. Ce travail a été mené en collaboration avec le CHU de Montpellier

Architectural stability of self-adaptive software systems

This thesis studies the notion of stability in software engineering with the aim of understanding its dimensions, facets and aspects, as well as characterising it. The thesis further investigates the aspect of behavioural stability at the architectural level, as a property concerned with the architecture's capability in maintaining the achievement of expected quality of service and accommodating runtime changes, in order to delay the architecture drifting and phasing-out as a consequence of the continuous unsuccessful provision of quality requirements. The research aims to provide a systematic and methodological support for analysing, modelling, designing and evaluating architectural stability. The novelty of this research is the consideration of stability during runtime operation, by focusing on the stable provision of quality of service without violations. As the runtime dimension is associated with adaptations, the research investigates stability in the context of self-adaptive software architectures, where runtime stability is challenged by the quality of adaptation, which in turn affects the quality of service. The research evaluation focuses on the effectiveness, scale and accuracy in handling runtime dynamics, using the self-adaptive cloud architectures

Ingénierie systèmes basée sur les modèles appliquée à la gestion et l'intégration des données de conception et de simulation : application aux métiers d'intégration et de simulation de systèmes aéronautiques complexes

The aim of this doctoral thesis is to contribute to the facilitation of design, integration and simulation activities in the aeronautics industry, but more generally in the context of collaborative complex product development. This objective is expected to be achieved through the use and improvement of digital engineering capabilities. During the last decade, the Digital Mock-Up (DMU) – supported by Product Data Management (PDM) systems – became a key federating environment to exchange/share a common 3D CAD model-based product definition between co-designers. It enables designers and downstream users(analysts) to access the geometry of the product assembly. While enhancing 3D and 2D simulations in a collaborative and distributed design process, the DMU offers new perspectives for analysts to retrieve the appropriate CAD data inputs used for Finite Element Analysis (FEA), permitting hence to speed-up the simulation preparation process. However, current industrial DMUs suffer from several limitations, such as the lack of flexibility in terms of content and structure, the lack of digital interface objects describing the relationships between its components and a lack of integration with simulation activities and data.This PhD underlines the DMU transformations required to provide adapted DMUs that can be used as direct input for large assembly FEA. These transformations must be consistent with the simulation context and objectives and lead to the concept of “Product View” applied to DMUs andto the concept of “Behavioural Mock-Up” (BMU). A product view defines the link between a product representation and the activity or process (performed by at least one stakeholder) that use or generate this representation as input or output respectively. The BMU is the equivalent of the DMU for simulation data and processes. Beyond the geometry, which is represented in the DMU,the so-called BMU should logically link all data and models that are required to simulate the physical behaviour and properties of a single component or an assembly of components. The key enabler for achieving the target of extending the concept of the established CAD-based DMU to the behavioural CAE-based BMU is to find a bi-directional interfacing concept between the BMU and its associated DMU. This the aim of the Design-Analysis System Integration Framework (DASIF) proposed in this PhD. This framework might be implemented within PLM/SLM environments and interoperate with both CAD-DMU and CAE-BMU environments. DASIF combines configuration data management capabilities of PDM systems with MBSE system modelling concepts and Simulation Data Management capabilities.This PhD has been carried out within a European research project: the CRESCENDO project, which aims at delivering the Behavioural Digital Aircraft (BDA). The BDA concept might consist in a collaborative data exchange/sharing platform for design-simulation processes and models throughout the development life cycle of aeronautics products. Within this project, the Product Integration Scenario and related methodology have been defined to handle digital integration chains and to provide a test case scenario for testing DASIF concepts. These latter have been used to specify and develop a prototype of an “Integrator Dedicated Environment” implemented in commercial PLM/SLM applications. Finally the DASIF conceptual data model has also served as input for contributing to the definition of the Behavioural Digital Aircraft Business Object Model: the standardized data model of the BDA platform enabling interoperability between heterogeneous PLM/SLM applications and to which existing local design environments and new services to be developed could plug.L’objectif de cette thèse est de contribuer au développement d’approches méthodologiques et d’outils informatiques pour développer les chaînes d’intégration numériques en entreprise étendue. Il s’agit notamment de mieux intégrer et d’optimiser les activités de conception, d’intégration et de simulation dans le contexte du développement collaboratif des produits/systèmes complexes.La maquette numérique (DMU) – supportée par un système de gestion de données techniques (SGDT ou PDM) – est devenue ces dernières années un environnement fédérateur clé pour échanger et partager une définition technique et une représentation 3D commune du produit entre concepteurs et partenaires. Cela permet aux concepteurs ainsi qu’aux utilisateurs en aval (ceux qui sont en charge des simulations numériques notamment) d’avoir un accès à la géométrie du produit virtuel assemblé. Alors que les simulations numériques 3D et 2D prennent une place de plus en plus importante dans le cycle de développement du produit, la DMU offre de nouvelles perspectives à ces utilisateurs pour récupérer et exploiter les données CAO appropriées et adaptées pour les analyses par éléments finis. Cela peut ainsi permettre d’accélérer le processus de préparation du modèle de simulation. Cependant, les environnements industriels de maquettes numériques sont actuellement limités dans leur exploitation par : - un manque de flexibilité en termes de contenu et de structure, - l’absence d’artefact numérique 3D permettant de décrire les interfaces des composants de l’assemblage, - un manque d’intégration avec les données et activités de simulation.Cette thèse met notamment l’accent sur les transformations à apporter aux DMU afin qu’elles puissent être utilisées comme données d’entrée directes pour les analyses par éléments finis d’assemblages volumineux (plusieurs milliers de pièces). Ces transformations doivent être en cohérence avec le contexte et les objectifs de simulation et cela nous a amené au concept de « vue produit » appliquée aux DMUs, ainsi qu’au concept de « maquette comportementale » (BMU). Une « vue produit » définit le lien entre une représentation du produit et l’activité ou le processus utilisant ou générant cette représentation. La BMU est l’équivalent de la DMU pour les données et les processus de simulation. Au delà des géométries discrétisées, la dénommée BMU devrait, en principe, lier toutes les données et les modèles qui seront nécessaires pour simuler le comportement d’un ou plusieurs composants. L’élément clé pour atteindre l’objectif d’élargir le concept établi de la DMU (basée sur des modèles CAO) à celui de la BMU (basée sur des modèles CAE), est de trouver un concept d’interface bidirectionnel entre la BMU et sa DMU associée. C’est l’objectif du « Design-Analysis System Integration Framework » (DASIF) proposé dans cette thèse de doctorat. Ce cadre a vise à être implémenté au sein d’environnements PLM/SLM et doit pouvoir inter-opérer à la fois avec les environnements CAD-DMU et CAE-BMU. DASIF allie les fonctionnalités de gestion de données et de configuration des systèmes PDM avec les concepts et formalismes d’ingénierie système basée sur les modèles (MBSE) et des fonctionnalités de gestion des données de simulation (SDM). Cette thèse a été menée dans le cadre d’un projet de recherche européen : le projet CRESCENDO qui vise à développer le « Behavioural Digital Aircraft » (BDA) qui a pour vocation d’être la« colonne vertébrale » des activités de conception et simulation avancées en entreprise étendue. Le concept du BDA doit s’articuler autour d’une plateforme collaborative d’échange et de partage des données de conception et de simulation tout au long du cycle de développement et de vie des produits aéronautiques. [...