Computer simulations have emerged as a cost efficient complement to laboratory experiments, as computers have become increasingly powerful. The aim of the present work is to explore the ideas of some state of the art software development practices, and ways in which these can be useful for developing high performance research codes. The introduction of these practices, and the modular designs that they give rise to, raises issues regarding a potential conflict between runtime efficiency on one hand and development efficiency on the other. Flexible software modules, based on mathematical abstractions, will provide support for convenient implementation and modification of numerical operators. Questions still remain about whether such modules will provide the efficiency which is required for high performance applications. To answer these questions, investigations were performed within two different problem domains. The first domain consisted of modular frameworks for the numerical solution of Partial Differential Equations. Such frameworks proved a suitable setting, since several of my research questions revolved around the issue of modularity. The second problem domain was that of symmetry exploiting algorithms. These algorithms are based on group theory, and make ample use of mathematical abstractions from that field. The domain of symmetry exploiting algorithms gave us opportunities to investigate difficulties in combining modularity based on high level abstractions with low level optimizations using data layout and parallelization. In conclusion, my investigation of software development practices for the area of high performance computing has proved very fruitful indeed. I have found that none of the concerns that were raised should lead us to refrain from the use of the practices that I have considered. On the contrary, in the two case studies presented here, these practices lead to designs that perform well in terms of usability as well as runtime efficiency.

Variability in complex systems offering rich set of features is a seriouschallenge to their users in term of flexibility with many possible variants fordifferent application contexts and maintainability. During the long period oftime, much effort has been made to deal with these issues. An effort in thisregard is developing and implementing different variability modelingtechniques.This thesis argues the explanation of three modeling techniques namedconfigurable components, feature models and function-means trees. The maincontribution to the research includes:• A comparison of above mentioned variability modeling techniques in asystematic way,• An attempt to find the integration possibilities of these modelingtechniques based on literature review, case studies, comparison,discussions, and brainstorming.The comparison is based on three case studies each of which is implemented inall above mentioned three modeling techniques and a set of generic aspects ofthese techniques which are further divided into characteristics. At the end, acomprehensive discussion on the comparison is presented and in final sectionsome integration possibility are proposed on the basis of case studies,characteristics, commonalities and experience gained through theimplementation of case studies and literature review.

Software product line engineering is a common method for designing complex software systems. Feature modeling is the most common approach to specify product lines. A feature model is a feature diagram (a special tree of features) plus some crosscutting constraints. Feature modeling languages are grouped into basic and cardinality-based models. The common understanding of the semantics of feature models is a Boolean semantics. We discuss a major deficiency of this semantics and fix it by applying, in turn, modal logic, the theory of multisets, and formal language theory. In order to adequately represent the semantics of basic models, we propose a Kripke semantics and show that basic feature modeling needs a modal rather than Boolean logic. We propose two multiset based theories for cardinality-based feature diagrams, called flat and hierarchical semantics. We show that the hierarchical semantics of a given cardinality-based diagram captures all information in the diagram. We also charac- terize sets of multisets, which can provide a hierarchical semantics of some diagrams. We provide three different reduction processes going from a cardinality-based diagram to an appropriate regular expression. As for crosscutting constraints, we propose a formal language interpretation of them. We also characterize some existing analysis operations over feature models in terms of operations on the corresponding languages and discuss the relevant decidability problems. / Thesis / Doctor of Philosophy (PhD)

La couche Infrastructure- as-a-Service (IaaS) de Cloud Computing offre un service de déploiement des images de machines virtuelles (VMIs) à la demande. Ce service fournit une plate-forme flexible pour les utilisateurs de cloud computing pour développer , déployer et tester leurs applications. Le déploiement d'une VMI implique généralement le démarrage de l'image, l'installation et la configuration des paquets de logiciels. Dans l'approche traditionnelle, lorsqu'un utilisateur de cloud demande une nouvelle plate-forme, le fournisseur de cloud sélectionne une image de modèle approprié pour cloner et déployer sur ​​les nœuds de cloud​​. L'image de modèle contient des paquets de logiciel pré-installés. Si elle ne correspond pas aux exigences, alors elle sera personnalisée ou la nouvelle image sera créé à partir de zéro pour s'adapter à la demande. Dans le cadre de la gestion des services de cloud, l'approche traditionnelle face aux questions difficiles de la manipulation de la complexité de l'interdépendance entre les paquets de logiciel, mise à l'échelle et le maintien de l' image déployée à l'exécution. Les fournisseurs de cloud souhaitent automatiser ce processus pour améliorer la performance de processus d'approvisionnement des VMIs, et de donner aux utilisateurs de cloud plus de flexibilité pour la sélection ou la création des images appropriées, tout en maximisant les avantages pour les fournisseurs en termes de temps, de ressources et de coût opérationnel. Cette thèse propose une approche pour gérer l'interdépendance des paquets de logiciels, pour modéliser et automatiser le processus de déploiement VMIs, et pour soutenir la reconfiguration VMIS à l'exécution, appelée l'approche dirigée par les modèle (Model-Driven approach). Nous nous adressons particulièrement aux défis suivants: (1) la modélisation de la variabilité des configurations d'image de machine virtuelle, (2) la réduction la quantité de transfert de données à travers le réseau, (3) l'optimisation de la consommation d'énergie des machines virtuelles; (4) la facilité à utiliser pour les utilisateurs de cloud; (5) l'automatisation du déploiement des VMIs; (6) le support de la mise à l'échelle et la reconfiguration de VMIS à l'exécution; (7) la manipulation de la topologie de déploiement complexe des VMIs . Dans notre approche, nous utilisons des techniques d'ingénierie dirigée par les modèles pour modéliser les représentations d'abstraction des configurations de VMI, le déploiement et les processus de reconfiguration d'image de machine virtuelle. Nous considérons que les VMIS comme une gamme de produits et utiliser les modèles de caractère pour représenter les configurations de VMIs. Nous définissons également le déploiement, les processus de reconfiguration et leurs facteurs (par exemple: les images de machines virtuelles, les paquets de logiciel, la plate-forme, la topologie de déploiement, etc.) comme les modèles. D'autre part, l'approche dirigée par les modèles s'appuie sur les abstractions de haut niveau de la configuration de VMIs et le déploiement de VMIs pour rendre la gestion d'images virtuelles dans le processus d'approvisionnement pour être plus flexible et plus facile que les approches traditionnelles. / The Cloud Computing Infastructure-as-a-Service (IaaS) layer provides a service for on demand virtual machine images (VMIs) deployment. This service provides a flexible platform for cloud users to develop, deploy, and test their applications. The deployment of a VMI typically involves booting the image, installing and configuring the software packages. In the traditional approach, when a cloud user requests a new platform, the cloud provider selects an appropriate template image for cloning and deploying on the cloud nodes. The template image contains pre-installed software packages. If it does not fit the requirements, then it will be customized or the new one will be created from scratch to fit the request. In the context of cloud service management, the traditional approach faces the difficult issues of handling the complexity of interdependency between software packages, scaling and maintaining the deployed image at runtime. The cloud providers would like to automate this process to improve the performance of the VMIs provisioning process, and to give the cloud users more flexibility for selecting or creating the appropriate images while maximizing the benefits for providers intern of time, resources and operational cost. This thesis proposes an approach to manage the interdependency of the software packages, to model and automate the VMIs deployment process, to support the VMIs reconfiguration at runtime, called the Model-Driven approach. We particularly address the following challenges: (1) modeling the variability of virtual machine image configurations; (2) reducing the amount of data transfer through the network; (3) optimizing the power consumption of virtual machines; (4) easy-to-use for cloud users; (5) automating the deployment of VMIs; (6) supporting the scaling and reconfiguration of VMIs at runtime; (7) handling the complex deployment topology of VMIs. In our approach, we use Model-Driven Engineering techniques to model the abstraction representations of the VMI configurations, the deployment and the reconfiguration processes of virtual machine image. We consider the VMIs as a product line and use the feature models to represent the VMIs configurations. We also define the deployment, re-configuration processes and their factors (e.g. virtual machine images, software packages, platform, deployment topology, etc.) as the models. On the other hand, the Model-Driven approach relies on the high-level abstractions of the VMIs configuration and the VMIs deployment to make the management of virtual images in the provisioning process to be more flexible and easier than traditional approaches.

<p>software product line is a set of software-intensive systems that share a common, managed set of features satisfying the specificneeds of a particular market segment or mission. The main attractive part of SPL is developing a set of common assets which includes requirements, design, test plans, test cases, reusable software components and other artifacts. Tools for the development of softwareproduct line are very few in number. The purpose of these tools is to support the creation, maintenance and using different versions ofproduct line artifacts. This requires a development environment that supports the management of assets and product development,processes and sharing of assets among different products.</p><p>The objective of this master thesis is to investigate the available tools which support Software Product Line process and itsdevelopment phases. The work is carried out in two steps, in the first step available Software Product Line tools are explored and a list of tools is prepared, managed and a brief introduction of each tool is presented. The tools are classified into different categoriesaccording to their usage, relation between the tools is established for better organization and understanding. In the second step, two tools Pure::variant and MetaEdit+ are selected and the quality factors such as Usability, Performance, Reliability, MemoryConsumption and Capacity are evaluated.</p>

A software product line is a set of software-intensive systems that share a common, managed set of features satisfying the specificneeds of a particular market segment or mission. The main attractive part of SPL is developing a set of common assets which includes requirements, design, test plans, test cases, reusable software components and other artifacts. Tools for the development of softwareproduct line are very few in number. The purpose of these tools is to support the creation, maintenance and using different versions ofproduct line artifacts. This requires a development environment that supports the management of assets and product development,processes and sharing of assets among different products. The objective of this master thesis is to investigate the available tools which support Software Product Line process and itsdevelopment phases. The work is carried out in two steps, in the first step available Software Product Line tools are explored and a list of tools is prepared, managed and a brief introduction of each tool is presented. The tools are classified into different categoriesaccording to their usage, relation between the tools is established for better organization and understanding. In the second step, two tools Pure::variant and MetaEdit+ are selected and the quality factors such as Usability, Performance, Reliability, MemoryConsumption and Capacity are evaluated.

The requirements for software products have increased in recent years. This is both due to more complex technology as well as more requirements from the customers. An approach to solve this issue is by using a software product line (SPL) where reusable assets are developed to produce more tailor-made products with reduced time to market. When creating reusable assets, one also wants to reuse the tests for them. In order to do that, it is important to understand what to test, and where to test. A good test strategy is thereby crucial in order to avoid testing becoming a bottleneck for efficient software development. The purpose of this thesis was to investigate how to create a good testing strategy for products in an SPL. This was done by collecting information about the current testing process in order to understand which requirements that exist and how they are addressed. The core foundation of an SPL is to utilize variation to create new products. To understand the existing variation of the product and the test cases a feature modeling and similarity analysis was done. The result from them made it possible to create a test strategy and categorization of test cases that can be used to ease the reuse of test cases for new variants of the product. The resulting test strategy presented proposes feature modeling as the basis of test creation and categorization as a tool to enable easier reuse of test cases. The results of the study indicate that using SPL theory in testing can introduce a better test strategy and test case creation process which is beneficial for the whole development process. / Kraven på mjukvaruprodukter har ökat de senaste åren. Detta beror delvis på mer komplicerad teknologi, men även på att kunderna ställer högre krav på de produkter de använder. Ett tillvägagångssätt för att lösa detta är att använda en software product line. I en software product line utvecklas återanvändningsbara delar som sedan kan kombineras och därmed skapa skräddarsydda produkter på ett mer effektivt sätt. När man skapar återanvändningsbara mjukvarudelar vill man också återanvända testerna för dem. För att göra det är det viktigt att förstå vad som ska testas och varför. En bra teststrategi är därmed avgörande för att undvika att testning blir en flaskhals för effektiv mjukvaruutveckling. Syftet med detta arbete var att undersöka hur man skapar en bra teststrategi för produkter i en software product line. Detta gjordes genom att samla in information om den nuvarande testprocessen för att förstå vilka krav som finns och hur de hanteras. En huvudaspekt i software product lineteori är att använda variation för att skapa nya produkter. För att förstå variationen i produkten och dess testfall gjordes en funktionsmodellering och likhetsanalys. Resultaten från dem gjorde det möjligt att skapa en teststrategi och en kategorisering av testfall som kan användas för att underlätta återanvändningen av testfall för nya varianter av produkten. Den resulterande teststrategin som presenteras föreslår funktionsmodellering som grund för testskapande och kategorisering som ett verktyg för att möjliggöra enklare återanvändning av testfall. Resultaten av studien tyder på att användning av software product lineteori vid testning kan resultera i en bättre teststrategi och enklare process för skapandet av nya testfall.

La Ingeniería de Líneas de Productos Software -Software Product Line Engineerings (SPLEs) en inglés- es una técnica de desarrollo de software que busca aplicar los principios de la fabricación industrial para la obtención de aplicaciones informáticas: esto es, una Línea de productos Software -Software Product Line (SPL)- se emplea para producir una familia de productos con características comunes, cuyos miembros, sin embargo, pueden tener características diferenciales. Identificar a priori estas características comunes y diferenciales permite maximizar la reutilización, reduciendo el tiempo y el coste del desarrollo. Describir estas relaciones con la suficiente expresividad se vuelve un aspecto fundamental para conseguir el éxito. La Ingeniería Dirigida por Modelos -Model Driven Engineering (MDE) en inglés- se ha revelado en los últimos años como un paradigma que permite tratar con artefactos software con un alto nivel de abstracción de forma efectiva. Gracias a ello, las SPLs puede aprovecharse en granmedida de los estándares y herramientas que han surgido dentro de la comunidad de MDE. No obstante, aún no se ha conseguido una buena integración entre SPLE y MDE, y como consecuencia, los mecanismos para la gestión de la variabilidad no son suficientemente expresivos. De esta manera, no es posible integrar la variabilidad de forma eficiente en procesos complejos de desarrollo de software donde las diferentes vistas de un sistema, las transformaciones de modelos y la generación de código juegan un papel fundamental. Esta tesis presenta MULTIPLE, un marco de trabajo y una herramienta que persiguen integrar de forma precisa y eficiente los mecanismos de gestión de variabilidad propios de las SPLs dentro de los procesos de MDE. MULTIPLE proporciona lenguajes específicos de dominio para especificar diferentes vistas de los sistemas software. Entre ellas se hace especial hincapié en la vista de variabilidad ya que es determinante para la especificación de SPLs. / Gómez Llana, A. (2012). MODEL DRIVEN SOFTWARE PRODUCT LINE ENGINEERING: SYSTEM VARIABILITY VIEW AND PROCESS IMPLICATIONS [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/15075

Designing and implementing coupled Earth System Models (ESMs) is a challenge for climate scientists and software engineers alike. Coupled models incorporate two or more independent numerical models into a single application, allowing for the simulation of complex feedback effects. As ESMs increase in sophistication, incorporating higher fidelity models of geophysical processes, developers are faced with the issue of managing increasing software complexity. Recently, reusable coupling software has emerged to aid developers in building coupled models. Effective reuse of coupling infrastructure means increasing the number of coupling functions reused, minimizing code duplication, reducing the development time required to couple models, and enabling flexible composition of coupling infrastructure with existing constituent model implementations. Despite the widespread availability of software packages that provide coupling infrastructure, effective reuse of coupling technologies remains an elusive goal: coupling models is effort-intensive, often requiring weeks or months of developer time to work through implementation details, even when starting from a set of existing software components. Coupling technologies are never used in isolation: they must be integrated with multiple existing constituent models to provide their primary services, such as model-to-model data communication and transformation. Unfortunately, the high level of interdependence between coupling concerns and scientific concerns has resulted in high interdependence between the infrastructure code and the scientific code within a model’s implementation. These dependencies are a source of complexity which tends to reduce reusability of coupling infrastructure. This dissertation presents mechanisms for increasing modeler productivity based on improving reuse of coupling infrastructure and raising the level of abstraction at which modelers work. This dissertation argues that effective reuse of coupling technologies can be achieved by decomposing existing coupling technologies into a salient set of implementation-independent features required for coupling high-performance models, increasing abstraction levels at which model developers work, and facilitating integration of coupling infrastructure with constituent models via component-based modularization of coupling features. The contributions of this research include: (1) a comprehensive feature model that identifies the multi-dimensional design space of coupling technologies used in high-performance Earth System Models, (2) Cupid, a domain-specific language and compiler for specifying coupling configurations declaratively and generating their implementations automatically, and (3) Component-based Coupling Operators (CC-Ops), a modular approach to code reuse of coupling infrastructure based on component technologies for high-performance scientific settings. The Cupid domain-specific language is evaluated by specifying a coupling configuration for an example fluid dynamics model and measuring the amount of code generated by the Cupid compiler compared to a hand coded version. The CC-Op approach is evaluated by implementing several CC-Ops using an existing high-performance component framework and measuring performance in terms of scalability and overhead.

Software Product Lines (SPLs) are a successful approach to software reuse in the large. Even though tools exist to create SPLs, their evolution is widely unexplored. Evolving an SPL manually is tedious and error-prone as it is hard to avoid unintended side-effects that may harm the consistency of the SPL. In this thesis, the conceptual basis of a system for the evolution of model-based SPLs is presented, which maintains consistency of models and feature mapping. As basis, a novel classification is introduced that distinguishes evolutions by their potential to harm the mapping of an SPL. Furthermore, multiple remapping operators are presented that can remedy the negative side-effects of an evolution. A set of evolutions is complemented with appropriate remapping operations for the use in SPLs. Finally, an implementation of the evolution system in the SPL tool FeatureMapper is provided to demonstrate the capabilities of the presented approach when co-evolving models and feature mapping of an SPL.