Lina Garcés

Quality attributes and quality models for ambient assisted living software systems: A systematic mapping

Abstract Context: Ambient Assisted Living (AAL) has become an essential, multidisciplinary research topic, aiming at providing software systems and services that assist people in their everyday life activities. Considering the critical nature of AAL systems, several initiatives have already contributed to the improvement of their quality, by mainly focusing on their non-functional requirements. Despite the importance of quality assurance in AAL systems, there is a lack of a comprehensive analysis on how quality assurance is performed in such systems. This fact might in turn lead to an absence of standardization with regard to the quality assurance process of these systems. Objective: We provide a broad, detailed panorama about the state of the art on quality models (QMs) and quality attributes (QAs) that are important for the AAL domain. Method: We performed a Systematic Mapping (SM). We used six publication databases to cover all published material pertinent for our SM. We initially obtained 287 studies that were filtered based on a set of well-defined inclusion/exclusion criteria, resulting into a set of 27 studies that were used for exploring QAs for AAL systems. Results: The most common QAs used in the development of AAL systems were identified and defined. We also characterized important critical attributes for software systems in the AAL domain. Additionally, QAs for some AAL sub-domains were defined. Furthermore, we investigated how QMQ (ii) considers variability of QAs among AAL sub-domains; (iii) analyses dependences among QAs; (iv) offers indicators or metrics to measure QAs; and (v) offers means to assess and predict quality of AAL systems.

ASAS: An Approach to Support Simulation of Smart Systems

Smart systems, such as smart cities, smart buildings, and autonomous cars, have recently gained increasing popularity. Each such system is essentially a System-of-Systems (SoS). SoS are dynamically established as alliances among independent and heterogeneous software systems to offer complex functionalities as a result of constituents interoperability. An SoS often supports critical application domains, and, as such, must be reliable. Many SoS have been specified and evaluated for their correct operation using static models. However, specification languages have not supported to capture their inherent dynamic nature nor enabled to monitor their operation. The main contribution of this paper is to present ASAS, an approach to Automatically generate Simulation models for smArt Systems (ASAS) in order to support evaluation of their operation. In particular, our approach makes it possible to transform formal models of the SoS architecture (expressed in SoSADL) into simulation models (expressed in DEVS). We evaluated our approach by conducting two case studies using a flood monitoring system that is intended to be part of a smart city. Results indicate that ASAS can successfully generate functional simulations for the SoS operation, which in turn can enable to reason and monitor an SoS operation, taking into account its dynamic nature. Keywords-System-of-Systems; Simulation; Model-Based Engineering.

Do we need new strategies for testing systems-of-systems?

This paper overviews the main Systems-of-Systems (SoS) characteristics that can impact on their verification, validation and testing (VV&T). Furthermore, it addresses technical, conceptual, social and organizational challenges, discusses which existing approaches of VV&T can be used for SoS, and points out future research in the field.

Two perspectives on reference architecture sustainability

In the context of software architectures, sustainability has been investigated as an important quality property to assess how well these architectures support changes over time. Several initiatives to achieve sustainable software architectures/systems can be already found. In parallel, reference architectures have served as an effective support to facilitate and standardize the development and evolution of software systems, including in complex, critical application domains. By encompassing valuable knowledge of specific domains, the reference architectures survival is considered of utmost importance, however, the most of such architectures have not been updated since their first version. Furthermore, there is a lack of works investigating how a reference architectures, by itself, can become sustainable and/or can contribute to develop sustainable systems in a domain. The main contribution of this paper is to provide a first view about sustainability on reference architectures. Resulting from our expertise on reference architectures, we bring out the two perspectives on their sustainability: (i) sustainability IN reference architectures; and (ii) sustainability OF reference architectures. In particular, for the perspective OF, we analyzed 20 existing reference architectures to assess their sustainability, and we found most of them were not updated over time. Hence, we also provide an initial set of aspects that could contribute to address sustainability of those architectures.

Software architecture and reference architecture of software-intensive systems and systems-of-systems: contributions to the state of the art

Complex software-intensive systems are more and more required as a solution for diverse critical application domains; at the same time, software architecture and also reference architecture have attracted attention as means to more adequately produce and evolve such systems. The main goal of this paper is to summarize our principal contributions in software architecture and reference architecture of software-intensive systems, including Systems-of-Systems. We intend this work can also inspire the opening of other related research lines towards founding the sustainability of such software-intensive systems.

Towards a Formal Description of Reference Architectures for Embedded Systems

Reference architectures systematize and standardize the development of software systems and, hence, contribute for the reuse of design expertise on a specific domain. An adequate architectural description for reference architectures is essential for their effective use and dissemination. Nonetheless, previous studies have pointed out that the architecture description of reference architectures often presents only informal, textual descriptions, which are ambiguity prone. The main purpose of this study is to discuss directions for a precise, comprehensive description which can support the specification, analysis, and realization of reference architectures. To do so, we investigate which and how formal methods could be introduced for describing reference architectures. Considering that components can be used for realizing reference architectures, we also investigate how they could be expressed in such a formal description. In particular, we focus on embedded systems due to the sophistication required for systems in this domain. With this study, we intend to contribute to the reference architecture community with directions for promoting a formal, precise architectural description.

Back-SoS: towards a model-based approach to address architectural drift in systems-of-systems

Systems-of-Systems (SoS) encompass independent, heterogeneous software-intensive systems (called constituents) that collaborate among themselves to accomplish larger missions. SoS architectures are inherently dynamic, which causes frequent reconfigurations that can quickly degrade the quality of the SoS architecture, as it can deviate from its initial prescriptive architecture, a phenomenon that has been referred to as architectural drift. Then, it is important to perform a reconciliation, i.e., a propagation of changes in the current concrete architecture to its associated prescriptive architecture, making them synchronized. The main contribution of this paper is proposing Back-SoS, a model-based approach that reconciles descriptive architecture of the SoS with its intended prescriptive architecture, thus supporting the verification of conformance between architectural configurations that can be obtained at runtime and their prescriptive design.

A process to establish, model and validate missions of systems-of-systems in reference architectures

Systems-of-Systems (SoSs) have risen in response to needs of achieving complex missions that can be only carried out from the cooperation among diverse, independent constituent systems. Understanding of missions and emergent behaviors in SoSs as well as the complicated interactions among constituent systems are a quite time demanding and challenging tasks. In another perspective, reference architectures (RAs) are a special type of software architecture that promotes reuse of knowledge to develop and evolve software systems, and mainly to promote interoperability among software systems. In spite of the relevance of RAs, these architectures have not still incorporated the concept of missions of SoSs and how to adequately manage them. Hence, such RAs have presented a limited ability to support SoSs development and evolution. In this scenario, the main contribution of this paper is to improve the feasibility of RAs in developing SoSs. For this, we present a systematic process to establish, model, and validate missions of SoSs and also incorporate them into RAs. To evaluate our process, we applied it in a RA for SoSs in the healthcare domain. Results achieved until now show that RAs designed considering our process could contribute to decrease expended time and effort at early stages of SoSs engineering.

A Quality Model for AAL Software Systems

The Ambient Assisted Living (AAL) domain aims to support the daily life activities of elders, patients with chronic conditions or disabled people, with a focus on ICT (Informatics and Communication Technologies). Important advances in AAL software systems have been already made, assisting people in their home, work, and social environments. Because of their critical nature, these systems must be developed focused on their quality. Hence, quality attributes (QAs), such as safety, reliability, and security, must be identified and well defined to successfully achieve the system purposes. However, there is not a set of QAs specific for AAL systems, hence, new systems have been developed based on general standards, such as ISO/IEC 25010, or based on particular experiences. This paper introduces the QM4AAL, a quality model (QM) for AAL systems. The QM4AAL was established and evaluated based on evidence from several published works found through conduction of a systematic mapping study. As result, the QM4AAL details QAs requirements, adaptive (e.g., self-configuring or situation-aware) or static properties, and stakeholders of AAL systems and their constituents systems (e.g., activity monitoring or health status monitoring systems). We intend this QM can orient the design and assessment of current and future AAL systems.