Ruzanna Chitchyan

Persistence as an aspect

Persistence - the storage and retrieval of application data from secondary storage media - is often used as a classical example of a crosscutting concern. It is widely assumed that an application can be developed without taking persistence requirements into consideration and a persistence aspect plugged in at a later stage. However, there are no real world examples showing whether persistence can in fact be aspectised and, if so, can this be done in a manner that promotes reuse and is oblivious to the application. In this paper, we provide an insight into these issues drawing upon our experience with a classical database application: a bibliography system. We argue that it is possible to aspectise persistence in a highly reusable fashion, which can be developed into a general aspect-based persistence framework. Nevertheless, application developers can only be partially oblivious to the persistent nature of the data. This is because persistence has to be accounted for as an architectural decision during the design of data-consumer components. Furthermore, designers of such components also need to consider the declarative nature of retrieval mechanisms supported by most database systems. Similarly, deletion requires explicit attention during application design as mostly applications trigger such an operation.

Semantics-based composition for aspect-oriented requirements engineering

In this paper, we discuss the limitations of the current syntactic composition mechanisms in aspect-oriented requirements engineering (AORE). We highlight that such composition mechanisms not only increase coupling between aspects and base concerns but are also insufficient to capture the intentionality of the aspect composition. Furthermore, they force the requirements engineer to reason about semantic influences and trade-offs among aspects from a syntactic perspective. We present a requirements description language (RDL) that enriches the existing natural language requirements specification with semantic information derived from the semantics of the natural language itself. Composition specifications are written based on these semantics rather than requirements syntax hence providing improved means for expressing the intentionality of the composition, in turn facilitating semantics-based reasoning about aspect influences and trade-offs. We also discuss the practicality of the use of this RDL by outlining the automation support for requirements annotation (realized as an extension of the Wmatrix natural language processing tool suite) to expose the semantics which are in turn utilized to facilitate composition and analysis (supported by the MRAT tool).

EA-Miner: a tool for automating aspect-oriented requirements identification

Aspect-Oriented requirements engineering helps to achieve early separation of concerns by supporting systematic analysis of broadly-scoped properties such as security, real-time constraints, etc. The early identification and separation of aspects and base abstractions crosscut by them helps to avoid costly refactorings at later stages such as design and code. However, if not handled effectively, the aspect identification task can become a bottleneck requiring a significant effort due to the large amount of, often poorly structured or imprecise, information available to a requirements engineer. In this paper, we describe a tool, EA-Miner, that provides effective automated support for identifying and separating aspectual and non-aspectual concerns as well as their crosscutting relationships at the requirements level. The tool utilises natural language processing techniques to reason about the properties of the concerns and model their structure and relationships.

Sustainability design and software: the karlskrona manifesto

Sustainability has emerged as a broad concern for society. Many engineering disciplines have been grappling with challenges in how we sustain technical, social and ecological systems. In the software engineering community, for example, maintainability has been a concern for a long time. But too often, these issues are treated in isolation from one another. Misperceptions among practitioners and research communities persist, rooted in a lack of coherent understanding of sustainability, and how it relates to software systems research and practice. This article presents a cross-disciplinary initiative to create a common ground and a point of reference for the global community of research and practice in software and sustainability, to be used for effectively communicating key issues, goals, values and principles of sustainability design for software-intensive systems.The centrepiece of this effort is the Karlskrona Manifesto for Sustainability Design, a vehicle for a much needed conversation about sustainability within and beyond the software community, and an articulation of the fundamental principles underpinning design choices that affect sustainability. We describe the motivation for developing this manifesto, including some considerations of the genre of the manifesto as well as the dynamics of its creation. We illustrate the collaborative reflective writing process and present the current edition of the manifesto itself. We assess immediate implications and applications of the articulated principles, compare these to current practice, and suggest future steps.

Aspect-Oriented Software Development in Practice: Tales from AOSD-Europe

Aspect-oriented software development techniques provide a means to modularize crosscutting concerns in software systems. A survey of industrial projects reveals the benefits and potential pitfalls of aspectoriented technologies.The past decade has seen the increased use of aspect-oriented software development (AOSD) technique as a means to modularize crosscutting concerns in software systems, thereby improving a development organizations working practices and return on investment (ROI). Numerous industrial-strength aspect-oriented (AO) programming frameworks exist, including AspectJ, JBoss, and Spring, as do various aspect-oriented analysis and design techniques.The software systems using AOSD that we have studied are medium to large-scale and span a wide range of domains including enterprise systems, e-health, e-transport, telecommunications, Web based information systems, multimedia applications, and workflow systems. Our analysis highlights typical usage patterns of AO techniques-for instance, they are mainly used for modularizing well-known crosscutting problems and incrementally introduced, addressing developmental concerns and other noncore product features first.

Requirements: The Key to Sustainability

Softwares critical role in society demands a paradigm shift in the software engineering mind-set. This shifts focus begins in requirements engineering. This article is part of a special issue on the Future of Software Engineering.

COMPASS: composition-centric mapping of aspectual requirements to architecture

Currently there are several approaches available for aspect-oriented requirements engineering and architecture design. However, the relationship between aspectual requirements and architectural aspects is poorly understood. This is because aspect-oriented requirements engineering approaches normally extend existing requirements engineering techniques. Although this provides backward compatibility, the composition semantics of the aspect-oriented extension are limited by those of the approaches being extended. Consequently, there is limited or no knowledge about how requirements-level aspects and their compositions map on to architecture-level aspects and architectural composition. In this paper, we present COMPASS, an approach that offers a systematic means to derive an aspect-oriented architecture from a given aspect-oriented requirements specification. COMPASS is centred on an aspect-oriented requirements description language (RDL) that enriches the usual informal natural language requirements with additional compositional information derived from the semantics of the natural language descriptions themselves. COMPASS also offers an aspect-oriented architecture description language (AO-ADL) that uses components and connectors as the basic structural elements (similar to traditional ADLs) with aspects treated as specific types of components. Lastly, COMPASS provides a set of concrete mapping guidelines, derived from a detailed case study, based on mapping patterns of compositions and dependencies in the RDL to patterns of compositions and dependencies in the AO-ADL. The mapping patterns are supported via a structural mapping of the RDL and AO-ADL meta-models.

Semantic vs. syntactic compositions in aspect-oriented requirements engineering: an empirical study

Most current aspect composition mechanisms rely on syntactic references to the base modules or wildcard mechanisms quantifying over such syntactic references in pointcut expressions. This leads to the well-known problem of pointcut fragility. Semantics-based composition mechanisms aim to alleviate such fragility by focusing on the meaning and intention of the composition hence avoiding strong syntactic dependencies on the base modules. However, to date, there are no empirical studies validating whether semantics based composition mechanisms are indeed more expressive and less fragile compared to their syntax-based counterparts. In this paper we present a first study comparing semantics- and syntax-based composition mechanisms in aspect-oriented requirements engineering (AORE). In our empirical study the semantics-based compositions examined were found to be indeed more expressive and less fragile. The semantics-based compositions in the study also required one to reason about composition interdependencies early on hence potentially reducing the overhead of revisions arising from later trade-off analysis and stakeholder negotiations. However, this added to the overhead of specifying the compositions themselves. Furthermore, since the semantics-based compositions considered in the study were based on natural language analysis, they required initial effort investment into lexicon building as well as strongly depended on advanced tool support to expose the natural language semantics.

A tool suite for aspect-oriented requirements engineering

Aspect-Oriented Requirements Engineering (AORE) supports identification of crosscutting, aspectual requirements as well as analysis of their influence on other requirements of the system. Identifying and analyzing aspectual requirements manually is very resource intensive due to their broadly scoped nature and the large volumes and ambiguity of input information from the stakeholders. In this paper we present a tool suite to support AORE in a scalable fashion. The tools support identification of aspectual requirements and their influences on other requirements, conflict detection and resolution between aspectual requirements, as well as requirements representation and requirements document structuring. A number of case studies, including two in an industrial setting, demonstrate the scalability and efficiency of the tool suite. They also show that its output is comparable to that of a requirements engineer carrying out the same tasks manually.

Sustainability design in requirements engineering: state of practice

Sustainability is now a major concern in society, but there is little understanding of how it is perceived by software engineering professionals and how sustainability design can become an embedded part of software engineering process. This paper presents the results of a qualitative study exploring requirements engineering practitioners’ perceptions and attitudes towards sustainability. It identifies obstacles and mitigation strategies regarding the application of sustainability design principlesin daily work life. The results of this study reveal several factors that can prevent sustainability design from becoming a first class citizen in software engineering: software practitioners tend to have a narrow understanding of the concept of sustainability; organizations show limited awareness of its potential opportunities and benefits; and the norms in the discipline are not conducive to sustainable outcomes. These findings suggest the need for focused efforts in sustainability education, but also a need to rethink professional norms and practices.