Elisa Yumi Nakagawa

Reference architecture and product line architecture: a subtle but critical difference

Currently, the size and complexity of software systems, as well as critical time to market, demand new approaches from Software Engineering discipline for building such systems. In this context, the use of reference architectures and product line architectures is becoming a common practice. However, both of these concepts are sometimes mistakenly seen as the same thing; it is also not clearly established how they can be explored in a complementary way in order to contribute to software development. The main contribution of this paper is to make a clear differentiation between these architectures, by investigating and establishing definitions for each of them. Based on this, we also propose the use of reference architectures as a basis for product line architectures. As a result, a better understanding of both reference architectures and product line architectures, as well as an understanding of how to explore them jointly, can contribute to promoting more effective reuse in the development of software systems.

RAModel: A Reference Model for Reference Architectures

Reference architectures have emerged as a special type of software architecture that achieves well-recognized understanding of specific domains, promoting reuse of design expertise and facilitating the development, standardization, and evolution of software systems. Designed for various domains and purpose, they have increasingly impacted important aspects of system development, such as productivity and quality of such systems. However, reference architectures have been sometimes established without an adequate concern about which elements they should encompass. Besides that, there is a lack of work that investigate the essence of reference architectures, their dimensions and elements that they should contain. In this perspective, the main contribution of this paper is to present a reference model for reference architectures, named RAModel (Reference Architecture Model), that intends to improve the understanding about what reference architectures are, as well as their components and relationships, supporting the establishment, use, and evolution of such architectures.

The state of the art and future perspectives in systems of systems software architectures

Currently, software systems have become increasingly large and complex, often resulted by the integration of several operationally independent systems, resulting in a new class of systems: the Systems of Systems (SoS). In another perspective, software architectures play a major role in determining system quality, since they form the backbone of any successful software-intensive system. Attention given to the software architectures of SoS is also certainly fundamental to the success of such systems. However, it is observed that there is a lack of works that present a wide and, at the same time, a detailed panorama about how SoS architectures have been treated. In this scenario, the main contribution of this paper is to present the state of the art on software architectures of SoS, mainly regarding their development, representation, evaluation, and evolution. This work also contributes with future research topics on SoS architectures that should be still investigated. Besides that, we intend this paper opens new perspectives of research in the software architecture area, intending to contribute to the success of SoS.

Automating the mutation testing of aspect-oriented Java programs

Aspect-Oriented Programming has introduced new types of software faults that may be systematically tackled with mutation testing. However, such testing approach requires adequate tooling support in order to be properly performed. This paper addresses this issue, introducing a novel tool named Proteum/AJ. Proteum/AJ realises a set of requirements for mutation-based testing tools and overcomes some limitations identified in previous tools for aspect-oriented programs. Through an example, we show how Proteum/AJ was designed to support the main steps of mutation testing. This preliminary use of the tool in a full test cycle provided evidences of the feasibility of using it in real software development processes and helped us to reason about the current functionalities and to identify future needs.

A systematic literature review on the description of software architectures for systems of systems

Software architectures have been recognized as the backbone to the success of any software system. In addition, they are responsible to aggregate quality attributes, such as interoperability, dependability, and maintainability, to these systems. In parallel, currently, a new class of complex software systems has emerged, referred as Systems of Systems (SoS), resulting from a number of operationally and managerially independent software systems working together to fulfill a mission that none system alone could provide. Considering their complexity, the development of SoS has demanded special attention to their software architectures. In this scenario, the description of such architectures, i.e., the way that these architectures are represented/documented, becomes quite important as it can improve communication as well as evaluation and maintenance of these architectures. Despite its relevance, there is still no complete panorama about architectural descriptions of SoS. The main contribution of this paper is to present results of a Systematic Literature Review (SLR) on how SoS software architectures have been described. As main result, there are already important contributions in that direction; however, there is a lack of consensus on how better dealing with these descriptions. We conclude this paper with directions on how a consensus could be achieved and which aspects of the SoS architectural descriptions require further investigation.

Software Architecture Relevance in Open Source Software Evolution: A Case Study

Software architecture has received increasing attention of practitioners and researchers, since it has played a significant role in determining the success and quality of software systems. At the same time, the success of open source software (OSS) has also sparked interest of researchers in the universities and in the software industry. OSS has been largely used and developed and, as a consequence, the OSS quality has been a concern and an interesting subject for researchers. However, in spite of narrow relation between software architecture and software quality, there is lack of more detailed works that investigate how software architecture can influence OSS quality. In this paper, we present a case study reporting how software architecture is directly related to OSS quality. We have hence proposed architecture refactoring activity in order to repair software architectures, aiming at improving mainly maintainability, functionality and usability of these systems.

An aspect-oriented reference architecture for Software Engineering Environments

Abstract: Reusable and evolvable Software Engineering Environments (SEEs) are essential to software production and have increasingly become a need. In another perspective, software architectures and reference architectures have played a significant role in determining the success of software systems. In this paper we present a reference architecture for SEEs, named RefASSET, which is based on concepts coming from the aspect-oriented approach. This architecture is specialized to the software testing domain and the development of tools for that domain is discussed. This and other case studies have pointed out that the use of aspects in RefASSET provides a better Separation of Concerns, resulting in reusable and evolvable SEEs.

Evaluation of AAL platforms according to architecture-based quality attributes

In the Ambient Assisted Living (AAL) domain, specific systems have been developed and applied to enable people with specific needs, such as elderly or disabled people, to live longer independently in their familiar residential environments. In order to support the development of such systems, a range of AAL platforms have been developed in recent years. However, there are considerable differences among these AAL platforms, particularly with respect to the treatment of important non-functional properties. This makes the selection of a suitable platform for a given AAL project very difficult. In order to support developers in this difficult task, we present an evaluation of relevant AAL platforms based on a selection of quality attributes that are important for AAL systems.

BAYESIAN-LEARNING BASED GUIDELINES TO DETERMINE EQUIVALENT MUTANTS

Mutation testing (Mutation Analysis), although powerful in revealing faults, is considered a computationally expensive criterion, due to the high number of mutants created and the effort to determi...

Consolidating a Process for the Design, Representation, and Evaluation of Reference Architectures

Reference architectures have emerged as a special type of software architecture that achieves well-recognized understanding of specific domains, promoting reuse of design expertise and facilitating the development, standardization, and evolution of software systems. Because of their advantages, several reference architectures have been proposed and have been also successfully used, including in the industry. However, the most of these architectures are still built using an ad-hoc approach, lacking of a systematization to their construction. If existing, these approaches could motivate and promote the building of new architectures and also support evolution of existing ones. In this scenario, the main contribution of this paper is to present the evolution of ProSA-RA, a process that systematizes the design, representation, and evaluation of reference architectures. ProSA-RA has been already applied in the establishment of reference architectures for different domains and this experience was used to evolve our process. In this paper, we illustrate an application of ProSA-RA in the robotics domain. Results achieved through the use of ProSA-RA have showed us that it is a viable, efficient process and, as a consequence, it could contribute to the reuse of knowledge in several applications domains, by promoting the establishment of new reference architectures.