Quality attribute trade-offs in the embedded systems industry: An exploratory case study

The embedded systems domain has grown exponentially over the past years. The industry is forced by the market to rapidly improve and release new products to beat the competition. Frenetic development rhythms thus shape this domain and give rise to several new challenges for software design and development. One of them is dealing with trade-offs between run-time and design-time quality attributes. To study practices, processes and tools concerning the management of run-time and design-time quality attributes as well as the trade-offs among them from the perspective of embedded systems software engineers. An exploratory case study with two qualitative data collection steps, namely interviews and a focus group, involving six different companies from the embedded systems domain with a total of twenty participants. The interviewed subjects showed a preference for run-time over design-time qualities. Trade-offs between design-time and run-time qualities are very common, but they are often implicit, due to the lack of adequate monitoring tools and practices. Practitioners prefer to deal with trade-offs in the most lightweight way possible, by applying ad-hoc practices, thus avoiding any overhead incurred. Finally, practitioners have elaborated on how they envision the ideal tool support for dealing with trade-offs. Although it is notoriously difficult to deal with trade-offs, constantly monitoring the quality attributes of interest with automated tools is key in making explicit and prudent trade-offs and mitigating the risk of incurring technical debt

Integration of Quality Attributes in Software Product Line Development

Different approaches for building modern software systems in complex and open environments have been proposed in the last few years. Some efforts try to apply Software Product Line (SPL) approach to take advantage of the massive reuse for producing software systems that share a common set of features. In general quality assurance is a crucial activity for success in software industry, but it is even more important when talking about Software Product Lines since the intensive reuse of assets makes the quality attributes (a measurable physical or abstract property of an entity) of the assets to be transmitted to the whole SPL scope. However, despite the importance that quality has in software product line development, most of the methodologies being applied in Software Product Line Development focus only on managing the commonalities and variability within the product line and not giving support to the non--¿ functional requirements that the products must fit. The main goal of this master final work is to introduce quality attributes in early stages of software product line development processes by means of the definition of a production plan that, on one hand, integrates quality as an additional view for describing the extension of the software product line and, on the other hand introduces the quality attributes as a decision factor during product configuration and when selecting among design alternatives. Our approach has been defined following the Model--¿ Driven Software Development paradigm. Therefore all the software artifacts defined had its correspondent metamodels and the processes defined rely on automated model transformations. Finally in order to illustrate the feasibility of the approach we have integrated the quality view in an SPL example in the context of safety critical embedded systems on the automotive domain.González Huerta, J. (2011). Integration of Quality Attributes in Software Product Line Development. http://hdl.handle.net/10251/15835Archivo delegad

Racial categories in machine learning

Controversies around race and machine learning have sparked debate among computer scientists over how to design machine learning systems that guarantee fairness. These debates rarely engage with how racial identity is embedded in our social experience, making for sociological and psychological complexity. This complexity challenges the paradigm of considering fairness to be a formal property of supervised learning with respect to protected personal attributes. Racial identity is not simply a personal subjective quality. For people labeled "Black" it is an ascribed political category that has consequences for social differentiation embedded in systemic patterns of social inequality achieved through both social and spatial segregation. In the United States, racial classification can best be understood as a system of inherently unequal status categories that places whites as the most privileged category while signifying the Negro/black category as stigmatized. Social stigma is reinforced through the unequal distribution of societal rewards and goods along racial lines that is reinforced by state, corporate, and civic institutions and practices. This creates a dilemma for society and designers: be blind to racial group disparities and thereby reify racialized social inequality by no longer measuring systemic inequality, or be conscious of racial categories in a way that itself reifies race. We propose a third option. By preceding group fairness interventions with unsupervised learning to dynamically detect patterns of segregation, machine learning systems can mitigate the root cause of social disparities, social segregation and stratification, without further anchoring status categories of disadvantage

The Perception of Technical Debt in the Embedded Systems Domain:An Industrial Case Study

Technical Debt Management (TDM) has drawn the attention of software industries during the last years, including embedded systems. However, we currently lack an overview of how practitioners from this application domain perceive technical debt. To this end, we conducted a multiple case study in the embedded systems industry, to investigate: (a) the expected life-time of components that have TD, (b) the most frequently occurring types of TD in them, and (c) the significance of TD against run-time quality attributes. The case study was performed on seven embedded systems industries (telecommunications, printing, smart manufacturing, sensors, etc.) from five countries (Greece, Netherlands, Sweden, Austria, and Finland). The results of the case study suggest that: (a) maintainability is more seriously considered when the expected lifetime of components is larger than ten years, (b) the most frequent types of debt are test, architectural, and code debt, and (c) in embedded systems the run-time qualities are prioritized compared to design-time qualities that are usually associated with TD. The obtained results can be useful for both researchers and practitioners: the former can focus their research on the most industrially-relevant aspects of TD, whereas the latter can be informed about the most common types of TD and how to focus their TDM processes

TRUSTED SERVICE COMPOSITION FOR DISTRIBUTED REAL-TIME AND EMBEDDED SYSTEMS

poster abstractDistributed real-time and embedded (DRE) software systems are expected to provide high quality-of-service (QoS) attributes, e.g., scalability, reliability, and security, in conjunction with correct functionality built atop of infrastructure with limited capabilities. Given the many complex and conflicting QoS and functional attributes of DRE systems, a major challenge in developing such software systems is to guaranteeing it trustworthiness, i.e., the degree of confidence that the system adheres to its specification. Current state-of-the-art methods use service orientation to compose systems from reusable and trusted services, and validate the trustworthiness of the end system using runtime evidences. The major shortcoming of this approach is that trust is considered an afterthought (i.e., not an integral part of the software development lifecycle). Trustworthiness of a system should be evaluated based on the trustworthiness of different properties of the system, including its functionality and QoS attributes. Our research extends current state-of-the-art methods for developing trusted DRE systems by considering development time factors of the composition (e.g., properties of individual services, interaction patterns, and compatibility with other services). It is a major research challenge to evaluate the composition of trustworthiness for different system properties with different composition patterns. Our current and future research work to address this challenge includes identifying trust composition operators for different types of compositions, deriving a formal model of trust composition, and validating our approach with a case study using a distributed tracking system

Applying patterns in embedded systems design for managing quality attributes and their trade-offs

Embedded systems comprise one of the most important types of software-intensive systems, as they are pervasive and used in daily life more than any other type, e.g., in cars or in electrical appliances. When these systems operate under hard constraints, the violation of which can lead to catastrophic events, the system is classified as a critical embedded system (CES). The quality attributes related to these hard constraints are named critical quality attributes (CQAs). For example, the performance of the software for cruise-control or self-driving in a car are critical as they can potentially relate to harming human lives. Despite the growing body of knowledge on engineering CESs, there is still a lack of approaches that can support its design, while managing CQAs and their trade-offs with noncritical ones (e.g., maintainability and reusability). To address this gap, the state-of-research and practice on designing CES and managing quality trade-offs were explored, approaches to improve its design identified, and the merit of these approaches empirically investigated. When designing software, one common approach is to organize its components according to well-known structures, named design patterns. However, these patterns may be avoided in some classes of systems such as CES, as they are sometimes associated with the detriment of CQAs. In short, the findings reported in the thesis suggest that, when applicable, design patterns can promote CQAs while supporting the management of trade-offs. The thesis also reports on a phenomena, namely pattern grime, and factors that can influence the extent of the observed benefits