The complex business applications are increasingly offered as services over the Internet, so-called software-as-a-Service (SaaS) applications. The SAP Netweaver Cloud offers an OSGI-based open platform, which enables multi-tenant SaaS applications to run in the cloud. A multi-tenant SaaS application is designed so that an application instance is used by several customers and their users. As different customers have different requirements for functionality and quality of the application, the application instance must be configurable. Therefore, it must be able to add new configurations into a multi-tenant SaaS application at run-time. In this thesis, we proposed concepts of a configuration management, which are used for managing and creating client configurations of cloud applications. The concepts are implemented in a tool that is based on Eclipse and extended feature models. In addition, we evaluate our concepts and the applicability of the developed solution in the SAP Netwaver Cloud by using a cloud application as a concrete case example.:List of Figures i List of Tables iii 1 Introduction 1 1.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.2 The Structure of This Document . . . . . . . . . . . . . . . . . 2 2 Background 5 2.1 Cloud Computing . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.2 Software Product Line Engineering . . . . . . . . . . . . . . . . 7 2.3 Role Based Access Control . . . . . . . . . . . . . . . . . . . . . 10 2.4 Staged Con guration . . . . . . . . . . . . . . . . . . . . . . . . 12 2.5 Work ow Modeling . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.5.1 Concept . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.5.2 Work ow Modeling Languages . . . . . . . . . . . . . . . 16 2.5.3 Adaptive Work ow . . . . . . . . . . . . . . . . . . . . . 17 2.5.4 Adaptation Patterns . . . . . . . . . . . . . . . . . . . . 17 2.6 Graph Transformation . . . . . . . . . . . . . . . . . . . . . . . 18 2.7 Related Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 3 Analysis 23 3.1 Illustrative Example . . . . . . . . . . . . . . . . . . . . . . . . 23 3.1.1 Domain and Exiting Platform . . . . . . . . . . . . . . . 24 3.1.2 Yard Management System as a SaaS Application . . . . 28 3.2 Requirements Identi cation . . . . . . . . . . . . . . . . . . . . 28 4 Concept 31 4.1 Con guration Management Speci cation . . . . . . . . . . . . . 31 4.1.1 Variability Modeling . . . . . . . . . . . . . . . . . . . . 32 4.1.2 Stakeholder Views Modeling . . . . . . . . . . . . . . . . 34 4.1.3 Con guration Work ow Modeling . . . . . . . . . . . . . 36 4.2 Con guration Work ow Adaptations . . . . . . . . . . . . . . . 41 4.3 Mapping between Problem Space and Solution Space . . . . . . 47 4.4 Con guration Process Simulation . . . . . . . . . . . . . . . . . 50 5 Implementation 53 5.1 Con guration Speci cation . . . . . . . . . . . . . . . . . . . . . 54 5.1.1 Extended Feature Model Speci cation . . . . . . . . . . 55 5.1.2 View Model Speci cation . . . . . . . . . . . . . . . . . . 56 5.1.3 Con guration Work ow Model Speci cation . . . . . . . 57 5.2 Graph Transformation Rules . . . . . . . . . . . . . . . . . . . . 62 5.3 Mapping Realization . . . . . . . . . . . . . . . . . . . . . . . . 65 5.4 Con guration Management Tooling . . . . . . . . . . . . . . . . 67 5.5 Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 6 Conclusions and Future Work 77 6.1 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 6.2 Future Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 Bibliography i

Une Ligne de Produits Logiciels (LPL) supporte la gestion d’une famille de logiciels. Cette approche se caractérise par une réutilisation systématique des artefacts communs qui réduit le coût et le temps de mise sur le marché et augmente la qualité des logiciels. Cependant, une LPL exige un investissement initial coûteux. Certaines organisations qui ne peuvent pas faire face à un tel investissement, utilisent le « Clone-and-own » C&O pour construire et faire évoluer des familles de logiciels. Cependant, l'efficacité de cette pratique se dégrade proportionnellement à la croissance de la famille de produits, qui devient difficile à maintenir. Dans cette thèse, nous proposons une approche hybride qui utilise à la fois une LPL et l'approche C&O pour faire évoluer une famille de produits logiciels. Un mécanisme automatique d’identification des correspondances entre les « features » caractérisant les produits et les artéfacts logiciels, permet la migration des variantes de produits développées en C&O dans une LPL. L’originalité de ce travail est alors d’aider à la dérivation de nouveaux produits en proposant différents scenarii d’opérations C&O à effectuer pour dériver un nouveau produit à partir des features requis. Le développeur peut alors réduire ces possibilités en exprimant ses préférences (e.g. produits, artefacts) et en utilisant les estimations de coûts sur les opérations que nous proposons. Les nouveaux produits ainsi construits sont alors facilement intégrés dans la LPL. Nous avons étayé cette thèse en développant le framework SUCCEED (SUpporting Clone-and-own with Cost-EstimatEd Derivation) et l’avons appliqué à une étude de cas sur des familles de portails web. / A Software Product Line (SPL) manages commonalities and variability of a related software products family. This approach is characterized by a systematic reuse that reduces development cost and time to market and increases software quality. However, building an SPL requires an initial expensive investment. Therefore, organizations that are not able to deal with such an up-front investment, tend to develop a family of software products using simple and intuitive practices. Clone-and-own (C&O) is an approach adopted widely by software developers to construct new product variants from existing ones. However, the efficiency of this practice degrades proportionally to the growth of the family of products in concern, that becomes difficult to manage. In this dissertation, we propose a hybrid approach that utilizes both SPL and C&O to develop and evolve a family of software products. An automatic mechanism of identification of the correspondences between the features of the products and the software artifacts, allows the migration of the product variants developed in C&O in an SPL The originality of this work is then to help the derivation of new products by proposing different scenarios of C&O operations to be performed to derive a new product from the required features. The developer can then reduce these possibilities by expressing her preferences (e.g. products, artifacts) and using the proposed cost estimations on the operations. We realized our approach by developing SUCCEED, a framework for SUpporting Clone-and-own with Cost-EstimatEd Derivation. We validate our works on a case study of families of web portals.

Adaptation enables a reaction to a changing environment. For traditional software development, that means changing the design and implementation of the software in a potentially complex and expensive process. If requirements are not known until the runtime of a software system, this system must be able to cope with changes during its runtime. For this, self-adaptive systems (SAS) were created. They have internal knowledge about themselves and their environment to reason about changes and take appropriate actions. Many approaches aiming to build such systems have been published since the start of the research area at the beginning of the 21st century. However, it is difficult to find an appropriate approach, even when all requirements of a scenario the system should be built for are known. If no suitable approach can be found, software developers have to built a new system leading to high development costs and potentially inefficient solutions due to the complexity of the system. This thesis follows two goals: (1) To make approaches building SAS more comparable through a feature model describing features of SAS, and (2) to provide a novel way of specifying SAS concisely using reference attribute grammars (RAGs) providing efficient systems. RAGs originate from the research field of compiler construction and enable the concise description of parts of the internal knowledge mentioned above as well as of the computation of the actions to cope with recognised changes. To make RAGs fully usable, this thesis presents two extensions: Relational RAGs enable the efficient handling of relations required for knowledge graphs, and Connected RAGs let RAG-based system communicate with other external systems to both recognise changes and execute actions. To evaluate the novel approaches, a classification of 30 approaches for the feature model and several case studies in the areas smart home, robotics, and system orchestration were conducted. It can be shown, that significantly less code is required to specify SAS. To specify the computation, 14.5 % to 28.7 % less code was required, whereas in another case study only 6.3 % of the total code was manually written and the rest was generated. The efficiency is similar to the best comparable approaches for graph queries. Furthermore, using additional optimizations (incremental evaluation), the execution time can be shown to be faster by a factor of 167.88 less albeit being sometimes by 50.0 % slower for very small workloads and specific queries. In a more realistic, extrapolated experiment, using incremental evaluation creates speed-up factors between 6.63 and 44.93. With the contributions in this thesis, existing approaches can be selected more precisely, new approaches can classify themselves within the research area, and the development of self-adaptive systems is possible using RAG-based systems.