Previously, software architects were unable to effectively and efficiently apply reusable knowledge (e.g., architectural styles and patterns) to architectural analyses. This work tackles this problem with a novel method to create and apply templates for reusable knowledge. These templates capture reusable knowledge formally and can efficiently be integrated in architectural analyses.

In this book, we introduce an automatic, experiment-based approach for performance problem diagnostics in enterprise software systems. The proposed approach systematically searches for root causes of detected performance problems by executing series of systematic performance tests. The presented approach is evaluated by various case studies showing that the presented approach is applicable to a wide range of contexts.

Die Software-Architektur umfasst die technische Organisation eines Software-Systems und die Prinzipien, die den Entwurf und die Evolution des Systems bestimmen. Die Problemstellung ergibt sich aus der Software-Evolution, wenn das System angepasst werden muss. Der Beitrag dieser Arbeit ist ein Verfahren zur Änderungsanfragenanalyse im Architekturmodell, welches die Ableitung von Tätigkeiten in nachgelagerten Tätigkeitsfeldern und Lebenszyklusphasen ermöglicht. Software Architecture covers the technical organization of a software system and principles which determine design and evolution of the system. The research issue of this work results from software evolution, when the software needs to be modified. The contribution of this book is a method for change request analysis based on software architecture models. The method supports derivation of tasks covering several work areas and life cycle phases.

We present a novel performance modeling approach tailored to I/O performance prediction in virtualized environments. The main idea is to identify important performance-influencing factors and to develop storage-level I/O performance models. To increase the practical applicability of these models, we combine the low-level I/O performance models with high-level software architecture models. Our approach is validated in a variety of case studies in state-of-the-art, real-world environments.

To understand the problems in metamodeling, this work presents an investigation of bad smells in metamodels. The core contribution of this work is the reference structure. It enables design, evolution, and extension of metamodels for modeling languages used for quality analysis. Applying the reference structure yields a modular metamodel. To be able to couple the metamodel modules in a meaningful way, this book investigates metamodel extension mechanisms.

This work introduces a novel approach to keep high-level component-based architecture models consistent with source code during software development and software evolution. The approach helps to avoid architecture drift and architecture erosion, which are two well-known problems that can arise during development and maintenance of a software system. In particular, the presented approach can be used to keep instances of the Palladio Component Model (PCM) consistent with Java source code.

This work presents an approach for the architecture analysis of energy efficiency for static and self-adaptive software systems. It introduces a modeling language that captures consumption characteristics on an architectural level. The outlined analysis predicts the energy efficiency of systems described with this language. Lastly, this work introduces an approach for considering transient effects in design time architecture analyses.

When complex IT systems are being developed, the usage of several programming and modelling languages can lead to inconsistencies that yield faulty designs and implementations. To address this problem, this work contributes a classification of consistency preservation challenges and an approach for preserving consistency. It is formalized using set theory and monitors changes to avoid matching and diffing problems. Three new languages that follow this preservation approach are presented.

Diese Arbeit stellt neuartige Konzepte zur effizienten Entscheidungsunterstützung in der Rekonfiguration software-intensiver technischer Systeme mit limitiertem Wartungszugriff vor. Entgegen rein redundanzorientierter Ansätze, basiert die verfolgte Methodik auf der prädiktiven Vorausberechnung adäquater Konfigurationsalternativen im relevanten Lösungsraum. Das Wissen über Konfigurationsbeziehung wird frühzeitig manifestiert und zur autarken kosteneffizienten Abwägung der Alternativen eingesetzt. This work presents novel concepts for efficient decision support in reconfiguring software-intensive technical systems with limited maintenance access. In contrast to purely redundancy-oriented approaches, the proposed methodology is based on the predictive pre-calculation of adequate configuration alternatives in the relevant design space. The knowledge about configuration relationships is manifested early and used for the autonomic cost-efficient assessment of configuration alternatives.

This work developed an automatic approach for the assessment of software reliability which is both theoretical sound and practical. The developed approach extends and combines theoretical sound approaches in a novel manner to systematically reduce the overhead of reliability assessment.