work for small problems, but it introduces signi?cant accidental complexities when tackling larger problems. Notethattherealchallengehereisnothowtodesignthesystemtotakeap- ticular aspect into account: there is signi?cant design know-how in industry on this and it is often captured in the form of design patterns. Taking into account more than one aspect can be a little harder, but many large scale successful projects in industry provide some evidence that engineers know how di?erent concerns should be handled. The real challenge is reducing the e?ort that the engineerhasto expendwhengrapplingwithmanyinter-dependentconcerns.For example, in a product-line context, when an engineer wants to replace a variant of an aspect used in a system, she should be able to do this cheaply, quickly and safely. Manually weaving every aspect is not an option. Unlike many models used in the sciences, models in software and in lingu- tics have the same nature as the things they model. In software, this provides an opportunity to automatically derive software from its model, that is, to - tomate the weaving process. This requires models to be formal, and the weaving process be described as a program (i.e., an executable meta-model) manipul- ing models to produce a detailed design. The detailed design produced by the weaving process can ultimately be transformed to code or at least test suites.

– Those who want to learn about AOM ?nd in this special issue a concise collection of descriptions of solid and mature AOM approaches. They only have to take the time to understand one case study in order to appreciate the sample models shown in all papers. – Those who want to apply AOM for a particular purpose and are looking for the most appropriate AOM technique can use the papers presented in this specialissue to identify the mostpromisingapproach(es).By identifying similarities between their problem and the case study they should be able to determine candidate AOM approaches easily. – Those working on their own AOM approach can readily identify approaches that were able to handle concerns that their own approach is not able to handle elegantly. This stimulates cross-fertilization between approaches and collaborative research. – Thoseengineering researchersthat areworkingon enhancing softwaredev- opment processes can use the example models presented in this special issue to understand the potential bene?ts of using AOM techniques at di?erent phases of the software development life-cycle.

This journal is devoted to aspect-oriented software development (AOSD) techniques in the context of all phases of the software life cycle, from requirements and design to implementation, maintenance and evolution. The focus of the journal is on approaches for systematic identification, modularization, representation and composition of crosscutting concerns, evaluation of such approaches and their impact on improving quality attributes of software systems.

Broadly-scoped requirements such as security, privacy, and response time are a major source of complexity in modern software systems. This is due to their tangled inter-relationships with and effects on other requirements. Aspect-Oriented Requirements Engineering (AORE) aims to facilitate modularisation of such broadly-scoped requirements, so that software developers are able to reason about them in isolation - one at a time. AORE also captures these inter-relationships and effects in well-defined composition specifications, and, in so doing exposes the causes for potential conflicts, trade-offs, and roots for the key early architectural decisions. Over the last decade, significant work has been carried out in the field of AORE. With this book the editors aim to provide a consolidated overview of these efforts and results. The individual contributions discuss how aspects can be identified, represented, composed and reasoned about, as well as how they are used in specific domains and in industry. Thus, the book does not present one particular AORE approach, but conveys a broad understanding of the aspect-oriented perspective on requirements engineering. The chapters are organized into five sections: concern identification in requirements, concern modelling and composition, domain-specific use of AORE, aspect interactions, and AORE in industry. This book provides readers with the most comprehensive coverage of AORE and the capabilities it offers to those grappling with the complexity arising from broadly-scoped requirements - a phenomenon that is, without doubt, universal across software systems. Software engineers and related professionals in industry, as well as advanced undergraduate and post-graduate students and researchers, will benefit from these comprehensive descriptions and the industrial case studies.

This volume presents two regular revised papers, a guest editors' introduction, and six papers in a special section that have been through a careful peer reviewing process by the journal's Editorial Board. Besides a wide range of topics from software design to implementation of aspect-oriented languages, the six papers of the special section concentrate on AOP systems, software and middleware.

The LNCS journal Transactions on Aspect-Oriented Software Development is devoted to all facets of aspect-oriented software development (AOSD) techniques in the context of all phases of the software life cycle, from requirements and design to implementation, maintenance and evolution. The focus of the journal is on approaches for systematic identification, modularization, representation and composition of crosscutting concerns, i.e., the aspects and evaluation of such approaches and their impact on improving quality attributes of software systems. This volume, the fifth in the Transactions on Aspect-Oriented Software Development series, contains three papers submitted through the regular channel, and three papers on the special focus area of aspects, dependencies and interactions. The first two papers concentrate on applications of AOSD to the fields of scheduling of web applications and operations research, respectively, while the third paper applies the technique of bisimulation to aspect-oriented languages. The special focus area on aspects, dependencies and interactions is introduced by the guest editors Ruzanna Chitchyan, Johan Fabry, Shmuel Katz, and Arend Rensink.

This journal is devoted to all facets of aspect-oriented software development (AOSD) techniques in the context of all phases of the software life cycle, from requirements and design to implementation, maintenance and evolution. The focus is on approaches for systematic identification, modularization, representation and composition of crosscutting concerns, i.e., the aspects and evaluation of such approaches and their impact on improving quality attributes of software systems.