Early aspects: aspect-oriented requirements engineering and architecture design

This paper reports on the third Early Aspects: Aspect-Oriented Requirements Engineering and Architecture Design Workshop, which has been held in Lancaster, UK, on March 21, 2004. The workshop included a presentation session and working sessions in which the particular topics on early aspects were discussed. The primary goal of the workshop was to focus on challenges to defining methodical software development processes for aspects from early on in the software life cycle and explore the potential of proposed methods and techniques to scale up to industrial applications

Composing Aspects at Shared Join Points

Aspect-oriented languages provide means to superimpose aspectual behavior on a given set of join points. It is possible that not just a single, but several units of aspectual behavior need to be superimposed on the same join point. Aspects that specify the superimposition of these units are said to "share" the same join point. Such shared join points may give rise to issues such as\ud determining the exact execution order and the dependencies among the aspects. In this paper, we present a detailed analysis of the problem, and identify a set of requirements upon mechanisms for composing aspects at shared join points. To address the identified issues, we propose a general and declarative model for defining constraints upon the possible compositions of aspects at a shared join point. Finally, by using an extended notion of join points, we show how concrete aspectoriented programming languages, particularly AspectJ and Compose*, can adopt the proposed model

Aspect-oriented domain analysis

Dissertação de Mestrado em Engenharia InformáticaDomain analysis (DA) consists of analyzing properties, concepts and solutions for a given domain of application. Based on that information, decisions are made concerning the software development for future application within that domain. In DA, feature modeling is used to describe common and variable requirements for software systems. Nevertheless, they show a limited view of the domain. In the mean time, requirement approaches can be integrated to specify the domain requirements. Among them, we have viewpoint oriented approaches that stand out by their simplicity, and efficiency organizing requirements. However, none of them deals with modularization of crosscutting subjects. A crosscutting subject can be spread out in several requirement documents. In this work we will use a viewpoint oriented approach to describe the domain requirements extended with aspects. Aspect-oriented domain analysis (AODA) is a growing area of interest as it addresses the problem of specifying crosscutting properties at the domain analysis level. The goal of this area is to obtain a better reuse at this abstraction level through the advantages of aspect orientation. The aim of this work is to propose an approach that extends domain analysis with aspects also using feature modeling and viewpoint

Leveraging service-oriented business applications to a rigorous rule-centric dynamic behavioural architecture.

Today’s market competitiveness and globalisation are putting pressure on organisations to join their efforts, to focus more on cooperation and interaction and to add value to their businesses. That is, most information systems supporting these cross-organisations are characterised as service-oriented business applications, where all the emphasis is put on inter-service interactions rather than intra-service computations. Unfortunately for the development of such inter-organisational service-oriented business systems, current service technology proposes only ad-hoc, manual and static standard web-service languages such as WSDL, BPEL and WS-CDL [3, 7]. The main objective of the work reported in this thesis is thus to leverage the development of service-oriented business applications towards more reliability and dynamic adaptability, placing emphasis on the use of business rules to govern activities, while composing services. The best available software-engineering techniques for adaptability, mainly aspect-oriented mechanisms, are also to be integrated with advanced formal techniques. More specifically, the proposed approach consists of the following incremental steps. First, it models any business activity behaviour governing any service-oriented business process as Event-Condition-Action (ECA) rules. Then such informal rules are made more interaction-centric, using adapted architectural connectors. Third, still at the conceptual-level, with the aim of adapting such ECA-driven connectors, this approach borrows aspect-oriented ideas and mechanisms, and proposes to intercept events, select the properties required for interacting entities, explicitly and separately execute such ECA-driven behavioural interactions and finally dynamically weave the results into the entities involved. To ensure compliance and to preserve the implementation of this architectural conceptualisation, the work adopts the Maude language as an executable operational formalisation. For that purpose, Maude is first endowed with the notions of components and interfaces. Further, the concept of ECA-driven behavioural interactions are specified and implemented as aspects. Finally, capitalising on Maude reflection, the thesis demonstrates how to weave such interaction executions into associated services

Integrating the theme approach with aspectual scenarios

Dissertação de Mestrado em Engenharia InformáticaAspect-oriented requirements engineering emerged to deal with crosscutting requirements, i.e. requirements that are scattered in the requirements document and tangled with other requirements. There are several aspect-oriented requirements approaches - Theme, proposed by Baniassad and Clarke [7], is one of them. This approach is characterized by the identification of a set of actions associated to verbs present in requirements documentation. These actions are then analyzed in order to identify crosscutting behaviours, each one constituting a potential theme. One problem with this approach is that the composition mechanism is not expressive enough even when the Theme models are integrated to analysis models (e.g. UML diagrams). The MATA approach [24] provides powerful composition mechanisms, based on graph transformations that used UML models, in particular behaviour models (e.g. sequence or activity like diagrams). These models express scenarios that constitute a very popular and used technique to specify a system’s behaviour. Therefore, the result of the integration of these two approaches will be synergetic. Also, considering that in a system not only the expected situations happen, scenarios can also be used to illustrate unexpected situations, making their treatment possible. Negative scenarios are thus also considered, besides the positive ones: their representation is similar, only differing from an optimist and mostly assumed vision of the system’s behavior. These scenarios could be identified with Theme and mapped into MATA. In summary, the objective of this dissertation is twofold: firstly, we will integrate Theme with Aspectual Scenarios (specified in MATA); secondly, we will extend Theme to include the modeling of negative scenarios. The result will be the synergy between two complementary techniques, including the specification of undesirable situations, where behavioral and structural aspect modeling are integrated

Metamodel for Tracing Concerns across the Life Cycle

Several aspect-oriented approaches have been proposed to specify aspects at different phases in the software life cycle. Aspects can appear within a phase, be refined or mapped to other aspects in later phases, or even disappear.\ud Tracing aspects is necessary to support understandability and maintainability of software systems. Although several approaches have been introduced to address traceability of aspects, two important limitations can be observed. First, tracing is not yet tackled for the entire life cycle. Second, the traceability model that is applied usually refers to elements of specific aspect languages, thereby limiting the reusability of the adopted traceability model.We propose the concern traceability metamodel (CTM) that enables traceability of concerns throughout the life cycle, and which is independent from the aspect languages that are used. CTM can be enhanced to provide additional properties for tracing, and be instantiated to define\ud customized traceability models with respect to the required aspect languages. We have implemented CTM in the tool M-Trace, that uses XML-based representations of the models and XQuery queries to represent tracing information. CTM and M-Trace are illustrated for a Concurrent Versioning System to trace aspects from the requirements level to architecture design level and the implementation

Comprehensive Aspectual UML Approach to Support AspectJ

Unified Modeling Language is the most popular and widely used Object-Oriented modelling language in the IT industry. This study focuses on investigating the ability to expand UML to some extent to model crosscutting concerns (Aspects) to support AspectJ. Through a comprehensive literature review, we identify and extensively examine all the available Aspect-Oriented UML modelling approaches and find that the existing Aspect-Oriented Design Modelling approaches using UML cannot be considered to provide a framework for a comprehensive Aspectual UML modelling approach and also that there is a lack of adequate Aspect-Oriented tool support. This study also proposes a set of Aspectual UML semantic rules and attempts to generate AspectJ pseudocode from UML diagrams. The proposed Aspectual UML modelling approach is formally evaluated using a focus group to test six hypotheses regarding performance; a “good design” criteria-based evaluation to assess the quality of the design; and an AspectJ-based evaluation as a reference measurement-based evaluation. The results of the focus group evaluation confirm all the hypotheses put forward regarding the proposed approach. The proposed approach provides a comprehensive set of Aspectual UML structural and behavioral diagrams, which are designed and implemented based on a comprehensive and detailed set of AspectJ programming constructs

Expressing aspectual interactions in requirements engineering: Experiences, problems and solutions

Aspect Oriented Requirements Engineering (AORE) provides support for modularizing crosscutting requirements. In the context of an industrial project in the domain of Slot Machines we needed to perform AORE, with a special emphasis on dependencies and interactions among concerns. We were however unable to find any report of large-scale industrial applications of AORE approaches that treat dependencies and interactions. We therefore evaluated two AORE approaches: Theme/Doc and MDSOCRE, to establish their applicability in our setting. In this paper we report on the limitations of both approaches we encountered and propose extensions that allow them to cope with concern interactions. We also show how these extensions provide the needed expressiveness by applying them to our industrial case study.Laboratorio de Investigación y Formación en Informática Avanzad