Abstract Quality requirements deal with how well a product should perform the intended functionality, such as start-up time and learnability. Researchers argue they are important and at the same time studies indicate there are deficiencies in practice. Our goal is to review the state of evidence for quality requirements. We want to understand the empirical research on quality requirements topics as well as evaluations of quality requirements solutions. We used a hybrid method for our systematic literature review. We defined a start set based on two literature reviews combined with a keyword-based search from selected publication venues. We snowballed based on the start set. We screened 530 papers and included 84 papers in our review. Case study method is the most common (43), followed by surveys (15) and tests (13). We found no replication studies. The two most commonly studied themes are (1) differentiating characteristics of quality requirements compared to other types of requirements, (2) the importance and prevalence of quality requirements. Quality models, QUPER, and the NFR method are evaluated in several studies, with positive indications. Goal modeling is the only modeling approach evaluated. However, all studies are small scale and long-term costs and impact are not studied. We conclude that more research is needed as empirical research on quality requirements is not increasing at the same rate as software engineering research in general. We see a gap between research and practice. The solutions proposed are usually evaluated in an academic context and surveys on quality requirements in industry indicate unsystematic handling of quality requirements.

Abstract Software engineering is decision intensive. Evidence‐based software engineering is suggested for decision‐making concerning the use of methods and technologies when developing software. Software development often includes the reuse of software assets, for example, open‐source components. Which components to use have implications on the quality of the software (e.g., maintainability). Thus, research is needed to support decision‐making for composite software. This paper presents a roadmap for research required to support evidence‐based decision‐making for choosing and integrating assets in composite software systems. The roadmap is developed as an output from a 5‐year project in the area, including researchers from three different organizations. The roadmap is developed in an iterative process and is based on (1) systematic literature reviews of the area; (2) investigations of the state of practice, including a case survey and a survey; and (3) development and evaluation of solutions for asset identification and selection. The research activities resulted in identifying 11 areas in need of research. The areas are grouped into two categories: areas enabling evidence‐based decision‐making and those related to supporting the decision‐making. The roadmap outlines research needs in these 11 areas. The research challenges and research directions presented in this roadmap are key areas for further research to support evidence‐based decision‐making for composite software.

Today, the newly available embedded boards with GPUs provide a solution to satisfy the ever-increasing requirements of modern embedded systems. Component-based development is a well-known paradigm ...

Platforms equipped with GPU processors help mitigating the ever-increasing computational demands of modern embedded systems. Such systems can be specifically developed by using component-based development thanks to the concept of flexible components. Through this concept, a component can be transparently executed either on a CPU or a GPU. However, this flexibility complicates the allocation process because it adds additional complexity (i.e., due to the undecided CPU or GPU execution) and constraints to consider (i.e., CPUs and GPUs properties) In this work, we address this problem by providing an optimization model for component-based embedded systems executing on both CPU and GPU. The model addresses important optimization goals, characteristic to the embedded system domain, such as memory usage, energy usage and execution time. A novelty of this work is the formal description of the optimization model, which supports the usage of mixed integer nonlinear programming to compute optimal allocation schemes. To examine the feasibility of the proposed method, we apply the optimization model on a vision system constructed using the industrial Rubus component model.

The choice of which software component to use influences the success of a software system. Only a few empirical studies investigate how the choice of components is conducted in industrial practice. This is important to understand to tailor research solutions to the needs of the industry. Existing studies focus on the choice for off-the-shelf (OTS) components. It is, however, also important to understand the implications of the choice of alternative component sourcing options (CSOs), such as outsourcing versus the use of OTS. Previous research has shown that the choice has major implications on the development process as well as on the ability to evolve the system. The objective of this study is to explore how decision making took place in industry to choose among CSOs. Overall, 22 industrial cases have been studied through a case survey. The results show that the solutions specifically for CSO decisions are deterministic and based on optimization approaches. The non-deterministic solutions proposed for architectural group decision making appear to suit the CSO decision making in industry better. Interestingly, the final decision was perceived negatively in nine cases and positively in seven cases, while in the remaining cases it was perceived as neither positive nor negative.

Today, embedded systems incorporate GPUs through a multitude of different architectures. When it comes to the development of these systems with GPUs, component-based development is ill-equipped as it does not provide support for GPUs. Instead, the component developer needs to encapsulate inside the component, besides functionality, settings and environment information that are specific to a particular GPU architecture. This binds the component this GPU architecture. Using these hardware-specific components characterized by restricted reusability, the system developer is confined to a limited design-space which may negatively impact the overall system feasibility. In this paper, we introduce the concept of flexible components, which are components that can be executed indifferently on CPU or GPU, regardless of the architecture. Using flexible components, component developers are relieved from the side development activities (e.g., environment information) which are automatically handled by component-level mechanisms. To enhance component communications, connection elements (i.e., adapters) are generated to handle component data transmission, taking in consideration the platform characteristics. Finally, our proposed solution is evaluated by using flexible components to implement the vision system of an underwater robot, and execute it on three platforms with different GPU architectures.

This paper introduces a decision canvas for capturing architecture decisions in software and systems engineering. The canvas leverages a dedicated taxonomy, denoted GRADE, meant for establishing the basics of the vocabulary for assessing and choosing architectural assets in the development of software-intensive systems. The canvas serves as a template for practitioners to discuss and document architecture decisions, i.e., capture, understand and communicate decisions among decision-makers and to others. It also serves as a way to reflect on past decision-making activities devoted to both tentative and concluding decisions in the development of software-intensive systems. The canvas has been assessed by means of preliminary internal and external evaluations with four scenarios. The results are promising as the canvas fulfills its intended objectives while satisfying most of the needs of the subjects participating in the evaluation.

Nowadays, there are many embedded systems with different architectures that have incorporated GPUs. However, it is difficult to develop CPU-GPU embedded systems using component-based development (CBD), since existing CBD approaches have no support for GPU development. In this context, when targeting a particular CPU-GPU platform, the component developer is forced to construct hardware-specific components, which are problematic to (re-)use in different contexts. Moreover, hard-coding specific GPU-usage characteristics (e.g., the number of utilized GPU threads) inside the component is not possible without making detailed assumptions about the system in which the component is used, which conflicts with separation-of-concerns CBD principle. The paper presents a solution to allow component-based development of platform-agnostic CPU-GPU embedded systems through: i) high-level API, ii) adapters, and iii) code template. The API abstracts the specifics of the different platforms, while the adapters externalize hardware-specific activities outside components. We also raise the decision regarding the GPU-usage specifications, from the component to the system level. Furthermore, to minimize the development effort, we provide a code template that contains ready-made code fragments required for GPU development. As a case study, we examine the feasibility of our solution applied on a component-based vision system of an underwater robot.

Efficient development of high quality software is tightly coupled to the ability of quickly taking complex decisions based on trustworthy facts. In component-based software engineering, the decisions related to selecting the most suitable component among functionally-equivalent ones are of paramount importance. Despite sharing the same functionality, components differ in terms of their extra-functional properties. Therefore, to make informed selections, it is crucial to evaluate extra-functional properties in a systematic way. To date, many properties and evaluation methods that are not necessarily compatible with each other exist. The property model ontology presented in this paper represents the first step towards providing a systematic way to describe extra-functional properties and their evaluation methods, and thus making them comparable. This is beneficial from two perspectives. First, it aids researchers in identifying comparable property models as a guide for empirical evaluations. Second, practitioners are supported in choosing among alternative evaluation methods for the properties of their interest. The use of the ontology is illustrated by instantiating a subset of property models relevant in the automotive domain.

Settling down the software architecture for embedded system is a complex and time consuming task. Specific concerns that are generally issued from implementation details must be captured in the software architecture and assessed to ensure system correctness. The matter is further complicated by the inherent complexity and heterogeneity of the targeted systems, platforms and concerns. In addition, tools capable of conjointly catering for the complete design-verification deployment cycle, extra-functional properties and reuse are currently lacking. To address this, we have developed Pride, an integrated development environment for component-based development of embedded systems. Pride is based on an architecture relying on components with well-defined semantics that serve as the central development entity, and as means to support and aggregate various analysis and verification techniques throughout the development -- from early specification to synthesis and deployment. Pride also provides generic support for integrating extra-functional properties into architectural definitions.

In the last decade, a large number of different software component models have been developed, with different aims and using different principles and technologies. This has resulted in a number of models which have many similarities, but also principal differences, and in many cases unclear concepts. Component-based development has not succeeded in providing standard principles, as has, for example, object-oriented development. In order to increase the understanding of the concepts and to differentiate component models more easily, this paper identifies, discusses, and characterizes fundamental principles of component models and provides a Component Model Classification Framework based on these principles. Further, the paper classifies a large number of component models using this framework.

The paper presents Save-IDE, an integrated development environment for the development of component-based embedded systems. Save-IDE supports efficient development of dependable embedded systems by providing tools for design of embedded software systems using a dedicated component model, formal specification and analysis of component and system behaviors already in early development phases, and a fully automated transformation of the system of components into an executable image.

In this paper, we present an approach allowing dynamic reconfiguration in wireless sensor networks (WSNs). This proposition is based on a twofold work. First we propose Valentine, a new component-based operating system (OS) for WSNs, allowing dynamic administration of components at runtime. This OS will be generated from the Think framework. Second, we discuss and present a specific mechanism for dynamic reconfiguration in the constrained context of WSNs.

In this paper we propose to use components for managing the increasing complexity in modern vehicular systems. Compared to other approaches, the distinguishing feature of our work is using and benefiting from components throughout the development process from early design to development and deployment, and an explicit separation of concerns at different levels of granularity. Based on the elaboration of the specifics of vehicular systems (resource constraints, real-time requirements, hard demands on reliability), the paper identifies concerns that need to be addressed by a component model for this domain, and describes a realization of such a component model.

In this paper we present an Integrated Development Environment Save-IDE, a toolset that embraces several tools: a tool for designing component-based systems and components, modeling and predicting certain run-time properties, such as timing properties, and transforming the components to real-time execution elements. Save-IDE is specialized for the domain of dependable embedded systems, which in addition to standard design tools requires tool support for analysis and verification of particular properties of such systems.