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The Hook model is used in digital products to engage and retain users through the mechanism of habit formation. This paper explores the use of Hook model techniques in two mobile applications, one being a popular taxi service (Uber taxi) and the other a social network (Instagram). The goal of this paper is to explore the Hook cycle patterns in the two products, and to identify commonalities and differences in how they are applied. Our results suggest that Hook cycle patterns appear with similar frequency; however, Instagram includes more internal Trigger calls. Uber uses fewer triggers to encourage usage, most probably because users already have a specific need for the application. For the same reason, Uber has less opportunity to fail in the reward delivery, while Instagram can use the failure (in providing a reward) as another trigger if the usage habit is already established. In addition, we introduce two types of Hook cycle patterns: internal (within a single use case) and external (transition between use cases). The insights obtained through the case studies serve as a practical reference for developing engaging and retention-focused applications. [ABSTRACT FROM AUTHOR]

In the early stage of software development, a software requirements specification (SRS) is essential, and whether the requirements are clear and explicit is the key. However, due to various reasons, there may be a large number of misunderstandings. To generate high-quality software requirements specifications, numerous researchers have developed a variety of ways to improve the quality of SRS. In this paper, we propose a questions extraction method based on SRS elements decomposition, which evaluates the quality of SRS in the form of numerical indicators. The proposed method not only evaluates the quality of SRSs but also helps in the detection of defects, especially the description problem and omission defects in SRSs. To verify the effectiveness of the proposed method, we conducted a controlled experiment to compare the ability of checklist-based review (CBR) and the proposed method in the SRS review. The CBR is a classic method of reviewing SRS defects. After a lot of practice and improvement for a long time, CBR has excellent review ability in improving the quality of software requirements specifications. The experimental results with 40 graduate students majoring in software engineering confirmed the effectiveness and advantages of the proposed method. However, the shortcomings and deficiencies of the proposed method are also observed through the experiment. Furthermore, the proposed method has been tried out by engineers with practical work experience in software development industry and received good feedback. [ABSTRACT FROM AUTHOR]

Software models' comparison is an operation performed in all software development lifecycle processes. Comparison is one of the steps of software models refactoring, refinement, merging, quality estimation, etc. Such operations take place in different tasks in requirement analysis, software designing, testing, reengineering, etc. This article proposes analytical foundations for software models' representation and corresponding technique for their comparison. To describe software model structure it is proposed to use graph representation. Software models' comparison technique based on subgraphs matching is proposed. Following this technique important steps of software tool realization are described, namely, (i) grounding of the choice of development environment and tools for XMI files processing; (ii) the algorithm for extracting software model structure from XMI file; (iii) software models' comparison algorithm realization; (iv) description of software architecture. Peculiarity of proposed software tool is a possibility for visualizing elements of two software models that do not match each other directly in modeling environment. Data are extracted from XMI files by means of LINQ queries. After that they are stored in graph triples. To perform visualization, it is proposed to modify "layout" files, designed by Microsoft Visual Studio environment. Other important feature of the tool is a possibility to compare software models, designed in different modeling environments. It is done by means of involving new LINQ queries, considering specifics of storing software models in different modeling environments. Paper contains case study, explaining the process of software models'analytical representation, and comparison technique implementation. [ABSTRACT FROM AUTHOR]

Software regression testing techniques verify previous functionalities each time software modifications occur or new characteristics are added. With the aim of gaining a better understanding of this subject, in this work we present a survey of software regression testing techniques applied in the last 15 years; taking into account its application domain, kind of metrics they use, its application strategies and the phase of the software development process where they are applied. From an outcome of 460 papers, a set of 25 papers describing the use of 31 software testing regression techniques were identified. Results of this survey suggest that at the time of applying a regression testing techniques, metrics like cost and fault detection efficiency are the most relevant. Most of the techniques were assessed with instrumented programs (experimental cases) under academic settings. Conversely, we observe a minimum set of software regression techniques applied in industrial settings, mainly, under corrective and maintenance approaches. Finally, we observe a trend using some regression techniques under agile approaches. [ABSTRACT FROM AUTHOR]

With the gradual maturity of component oriented software development method, component-based software evolution technology has become hot research in academia and industry. Although many evolution rules are designed, they rarely consider component type-mismatched problem in evolution rules. This has led to evolution rules that often run error in software evolution execution. Hence, focusing on the mismatch problem of component type in software evolution, this paper addresses various evolution rules with condition constrains to support component type matching. First, we use the bigraph theory to model the software architecture and employ bigraph term language to describe the basic component evolution operations. Second, we join type system into the term language and use the type term language to express the condition constraints on position and connection for component evolution rules. These condition constraints can guarantee the type-matched among components that participate in software evolution. Furthermore, we show that the component type-matched still kept during a number of different evolution rules are used in the whole software evolution reaction system. Finally, two cases study of evolution progress of ATM system and tourism information system are presented. Two cases illustrate the effectiveness of our approach. [ABSTRACT FROM AUTHOR]

Event-based communication is used in different domains including telecommunications, transportation, and business information systems to build scalable distributed systems. Such systems typically have stringent requirements for performance and scalability as they provide business and mission critical services. While the use of event-based communication enables loosely-coupled interactions between components and leads to improved system scalability, it makes it much harder for developers to estimate the system's behavior and performance under load due to the decoupling of components and control flow. In this paper, we present our approach enabling the modeling and performance prediction of event-based systems at the architecture level. Applying a model-to-model transformation, our approach integrates platform-specific performance influences of the underlying middleware while enabling the use of different existing analytical and simulation-based prediction techniques. In summary, the contributions of this paper are: (1) the development of a meta-model for event-based communication at the architecture level, (2) a platform aware model-to-model transformation, and (3) a detailed evaluation of the applicability of our approach based on two representative real-world case studies. The results demonstrate the effectiveness, practicability and accuracy of the proposed modeling and prediction approach. [ABSTRACT FROM AUTHOR]

The term solution space is widely used in the engineering community; yet there is little known about their evolution. Theoretical research in the field of systems science indicates that requirements can only reduce the solution space. Yet, some authors state that on the contrary requirements can be used to expand to or open new solution spaces. Furthermore, some practitioners defend that the requirement to use a previously nonexistent technology would actually increase the solution space or move it to a new area, while others state that more requirements make life more difficult. Who is right then? The present paper provides initial answers to this question using systems theory. In order to achieve this, the present paper differentiates between various types of solutions spaces, which depend on the systems they include. Finally, the paper provides practical examples to showcase the results of the theoretical findings within real contexts. [ABSTRACT FROM AUTHOR]

This paper will produce three areas of discussion in the field of cost estimation for unmanned autonomous systems. First, this paper will propose a common definition of an Unmanned Autonomous system. Second, it will introduce a method to estimate the cost of unmanned autonomous systems utilizing existing parametric cost estimation tools: SEER – HDR, COCOMO II, COSYSMO, and two relationships – weight and performance. The third discussion will focus on challenges surrounding autonomy. To address these challenges from a cost perspective, this paper recommends modifications to parameters within COCOMO II – via the use of object oriented function points in lieu of current methods, and COSYSMO – via the introduction of two cost driving parameters, namely, TVED and HRI-T. Finally, in summary this paper will identify areas of further research. [ABSTRACT FROM AUTHOR]

To predict the performance of an application, it is crucial to consider the performance of the underlying infrastructure. Thus, to yield accurate prediction results, performance-relevant properties and behaviour of the infrastructure have to be integrated into performance models. However, capturing these properties is a cumbersome and error-prone task, as it requires carefully engineered measurements and experiments. Existing approaches for creating infrastructure performance models require manual coding of these experiments, or ignore the detailed properties in the models. The contribution of this paper is the Goal-oriented INfrastructure Performance EXperiments ( Ginpex) approach, which introduces goal-oriented and model-based specification and generation of executable performance experiments for automatically detecting and quantifying performance-relevant infrastructure properties. Ginpex provides a metamodel for experiment specification and comes with predefined experiment templates that provide automated experiment execution on the target platform and also automate the evaluation of the experiment results. We evaluate Ginpex using three case studies, where experiments are executed to quantify various infrastructure properties. [ABSTRACT FROM AUTHOR]

Model composition plays a central role in many software engineering activities, e.g., evolving design models to add new features. To support these activities, developers usually rely on model composition heuristics. The problem is that the models to-be-composed usually conflict with each other in several ways and such composition heuristics might be unable to properly deal with all emerging conflicts. Hence, the composed model may bear some syntactic and semantic inconsistencies that should be resolved. As a result, the production of the intended model is an error-prone and effort-consuming task. It is often the case that developers end up examining all parts of the output composed model instead of prioritizing the most critical ones, i.e., those that are likely to be inconsistent with the intended model. Unfortunately, little is known about indicators that help developers (1) to identify which model is more likely to exhibit inconsistencies, and (2) to understand which composed models require more effort to be invested. It is often claimed that software systems remaining stable over time tends to have a lower number of defects and require less effort to be fixed than unstable systems. However, little is known about the effects of software stability in the context of model evolution when supported by composition heuristics. This paper, therefore, presents an exploratory study analyzing stability as an indicator of inconsistency rate and resolution effort on model composition activities. Our findings are derived from 180 compositions performed to evolve design models of three software product lines. Our initial results, supported by statistical tests, also indicate which types of changes led to lower inconsistency rate and lower resolution effort. [ABSTRACT FROM AUTHOR]

The accuracy of performance-prediction models is crucial for widespread adoption of performance prediction in industry. One of the essential accuracy-influencing aspects of software systems is the dependence of system behaviour on a configuration, context or history related state of the system, typically reflected with a (persistent) system attribute. Even in the domain of component-based software engineering, the presence of state-reflecting attributes (the so-called internal states) is a natural ingredient of the systems, implying the existence of stateful services, stateful components and stateful systems as such. Currently, there is no consensus on the definition or method to include state-related information in component-based prediction models. Besides the task to identify and localise different types of stateful information across component-based software architecture, the issue is to balance the expressiveness and complexity of prediction models via an effective abstraction of state modelling. In this paper, we identify and classify stateful information in component-based software systems, study the performance impact of the individual state categories, and discuss the costs of their modelling in terms of the increased model size. The observations are formulated into a set of heuristics-guiding software engineers in state modelling. Finally, practical effect of state modelling on software performance is evaluated on a real-world case study, the SPECjms2007 Benchmark. The observed deviation of measurements and predictions was significantly decreased by more precise models of stateful dependencies. [ABSTRACT FROM AUTHOR]

We have developed a new system for measuring dental, gnathic, and facial areas with cephalogram-equivalent images created from computed tomographic imaging data. An advantage of this collaborative system is that a measurement template and automated processing are used. First, experienced orthodontists were provided with the measurement templates; they then moved the measurement markers to the specified landmarks on the cephalogram in the template. Subsequently, the program automatically detected the coordinates of the markers and calculated the distance between those coordinates. The appropriate use of this system leads to highly accurate results in large quantities of measurements in a short time by means of both manual and automatic processing. The system was developed to contribute to worldwide research into dental and craniofacial measurements; the research involved 500 patients, and the system worked successfully. [ABSTRACT FROM AUTHOR]

Arc welding is a thermal plasma process widely used to join metals. An arc welding model that couples fluid dynamic and electromagnetic equations was initially developed as a research tool. Subsequently, it was applied to improve and optimise industrial implementations of arc welding. The model includes the arc plasma, the electrode, and the workpiece in the computational domain. It incorporates several features to ensure numerical accuracy and reduce computation time and memory requirements. The arc welding code has been refactored into commercial-grade Windows software, ArcWeld, to address the needs of industrial customers. The methods used to develop ArcWeld and its extension to new arc welding regimes, which used the Workspace workflow platform, are presented. The transformation of the model to an integrated software application means that non-experts can now run the code after only elementary training. The user can easily visualise the results, improving the ability to analyse and generate insights into the arc welding process being modelled. These changes mean that scientific progress is accelerated, and that the software can be used in industry and assist welders' training. The methods used are transferrable to many other research codes. [ABSTRACT FROM AUTHOR]

Model-Based Software Engineering (MBSE) is an architecture-based software development approach. Agile, on the other hand, is a light system development approach that originated in software development. To bring together the benefits of both approaches, this article proposes an integrated Agile MBSE approach that adopts a specific instance of the Agile approach (i.e., Scrum) in combination with a specific instance of an MBSE approach (i.e., Model-Based System Architecture Process—"MBSAP") to create an Agile MBSE approach called the integrated Scrum Model-Based System Architecture Process (sMBSAP). The proposed approach was validated through a pilot study that developed a health technology system over one year, successfully producing the desired software product. This work focuses on determining whether the proposed sMBSAP approach can deliver the desired Product Increments with the support of an MBSE process. The interaction of the Product Development Team with the MBSE tool, the generation of the system model, and the delivery of the Product Increments were observed. The preliminary results showed that the proposed approach contributed to achieving the desired system development outcomes and, at the same time, generated complete system architecture artifacts that would not have been developed if Agile had been used alone. Therefore, the main contribution of this research lies in introducing a practical and operational method for merging Agile and MBSE. In parallel, the results suggest that sMBSAP is a middle ground that is more aligned with federal and state regulations, as it addresses the technical debt concerns. Future work will analyze the results of a quasi-experiment on this approach focused on measuring system development performance through common metrics. [ABSTRACT FROM AUTHOR]

This year’s ICCS conference theme promotes the use of computational science as a means to foster multidisciplinarity and synergies with other fields. Our thesis is that this trend towards multidisciplinarity should be accompanied by the use of best practices issued from the software engineering community in order to avoid obtaining overly complex and tangled code, difficult to validate, to maintain and to port. In this paper we argue for the need of applying separation of concerns principles when the development involves scientists from various application fields. We overview several strategies that may be used to achieve this separation, focusing mainly on two approaches drawn from our previous experiences with multidisciplinary projects, addressing two distinct patterns of multi-domain interaction that may occur in scientific software development. [ABSTRACT FROM AUTHOR]

This paper documents four years of a novel approach to teaching a two-course sequence in software engineering as part of the ABET-accredited computer science curriculum at the College of Charleston. This approach is team-based and centers on learning software engineering in the context of open source software projects. In the first course, teams develop automated testing frameworks for their chosen free open source software (FOSS) project, and in the second course, team members join and contribute to a selected open source project, documenting the process through regular blog and wiki posts and an oral presentation. Results point to the transformative nature of such coursework on students' perception of software engineering. Discussion focuses on potential future iterations of this capstone model. [ABSTRACT FROM AUTHOR]

In an effort to explore the relationship between the disciplines of systems engineering and software engineering, professionals from academia, industry, and government gathered for a workshop to deliberate on the current state, to acknowledge areas of inter-dependence, to identify relevant challenges, and to propose recommendations for addressing those challenges with respect to four topical areas: 1) Development Approaches, 2) Technical, 3) People, and 4) Education. This paper presents the deliberations and recommendations that emerged from that workshop, and the proposed project to be launched. [ABSTRACT FROM AUTHOR]

Instead of developing each new product from scratch, firms strive to reuse prior components and technologies in new applications in order to improve robustness, reduce cost and shorten time-to-market. Technologies come in the forms of methods, designs and processes, and are suitable for reuse since they are concepts for solving certain problems that multiple products have use for. However, reuse of technology where the application context is different requires adaptation of both the technology and the product system into which it is introduced. In practice, the magnitude and sources for this effect are often underestimated, which leads to unanticipated uncertainty in product development projects with consequences for robustness and efficiency in development. Based on available literature and needs identified within a case company, this paper proposes a method for identifying potential challenges of technology reuse that may otherwise be overlooked or only implicitly acknowledged. The method features a scorecard that guides a workshop to be attended by technology experts and managers where the prospect for successful technology reuse is assessed. [ABSTRACT FROM AUTHOR]

The systems development, procurement and sustainment of a nation's military equipment is vital to its national interests, but the process is complex, constantly changing and highly adaptive, as well as time consuming and costly. The U.S. Department of Defense (DoD) expends both large amounts of capital and manpower to equip its armed forces. This research seeks to identify opportunities to gain better insight into the functioning of the defense acquisition system, building on previous simulations. A case is made that the DoD Requirements, Planning Acquisition, Technology and Logistics System is a complex adaptive system that has characteristics appropriate for exploration with agent-based modeling. This paper reviews relevant literature, existing models and presents preliminary analysis on an agent-based simulation of the DoD acquisition system. This research finds that agent-based modeling can provide insights to inform new acquisition theory. [ABSTRACT FROM AUTHOR]

Sustainable computing is a rapidly growing research topic spanning several areas of Computer Science. Particularly, it has received increasing attention in the Software Engineering field in the last years, with several studies discussing the topic from a range of perspectives. However, few studies have demonstrated the awareness of software practitioners about the underlying concepts of sustainability in the software development practice. In an earlier investigation, we performed a preliminary study on the practitioners' perception under four main perspectives: economic, social, environmental, and technical. This study extended the previous survey and reached a number of ninety-seven respondents from Brazilian companies. The extension aims to expand the results to compare and explore the previous findings in a more in-depth way. The novel results confirmed the evidence raised in the original survey that sustainability in the context of Software Engineering is a new subject for practitioners. However, professionals have shown interest in the topic, and there is a general understanding that sustainability should be treated as a quality attribute. Among the observed perspectives, we generated an initial theory that shows software practitioners know the subject around 'Green in Software', even unconsciously. This study brings evidence of how the industry understands and perceives sustainability practices in the software development process. [ABSTRACT FROM AUTHOR]

Current software engineering efforts typically rely heavily on industrial infrastructure. In a situation of civilizational collapse -- which various researchers have suggested could ensue in the next century via an assortment of environmental, economic, and/or social pathways -- this infrastructure may become less reliable. Previous research has offered some thoughts about what new forms of software may be relevant in the context of collapse. However, those papers did not consider how these new kinds of software would arise. Building on previous work in software engineering for sustainability (SE4S), information and communications technology for development (ICT4D), and collapse informatics, this paper explores how various forms of civilizational collapse would affect the software development process. [ABSTRACT FROM AUTHOR]

Many scientific disciplines rely on computational methods for data analysis, model generation, and prediction. Implementing these methods is often accomplished by researchers with domain expertise but without formal training in software engineering or computer science. This arrangement has led to underappreciation of sustainability and maintainability of scientific software tools developed in academic environments. Some software tools have avoided this fate, including the scientific library Rosetta. We use this software and its community as a case study to show how modern software development can be accomplished successfully, irrespective of subject area. Rosetta is one of the largest software suites for macromolecular modeling, with 3.1 million lines of code and many state-of-the-art applications. Since the mid 1990s, the software has been developed collaboratively by the RosettaCommons, a community of academics from over 60 institutions worldwide with diverse backgrounds including chemistry, biology, physiology, physics, engineering, mathematics, and computer science. Developing this software suite has provided us with more than two decades of experience in how to effectively develop advanced scientific software in a global community with hundreds of contributors. Here we illustrate the functioning of this development community by addressing technical aspects (like version control, testing, and maintenance), community-building strategies, diversity efforts, software dissemination, and user support. We demonstrate how modern computational research can thrive in a distributed collaborative community. The practices described here are independent of subject area and can be readily adopted by other software development communities. [ABSTRACT FROM AUTHOR]

Equal access to all software and digital content should be a reality in the Digital Era. This argument is something defended both by existing regulations, norms and standards, and also business organizations and governments. Despite this acknowledgement, the reality is still far from the desired equality. For certain groups of disabled or impaired citizens, such as the visually impaired, the existence of e-accessibility compliance represents an opportunity to integrate, in a more simple and straightforward manner, their societies. Despite the existing poor results on e-accessibility compliance, the mentioned citizens insist on using digital devices in their daily lives. Even though, in the last decade, multiple standards and regulations have been published towards indicating how to develop accessible digital user interfaces, there are still two major issues surrounding its implementation: the complexity and disparity of the documents containing the abovementioned norms, and also the lack of e-accessibility know-how by software experts. With this in mind, a proposal for an accessible software development model that encompasses e-accessibility incorporation as one of the development process activities has been presented. This model might represent a very interesting support tool for software development organizations and a novel resource for learning and training institutions to be able to improve their computer science and informatics students' skills on e-accessibility. [ABSTRACT FROM AUTHOR]

Software testing is an essential activity in software development projects for delivering high quality products. In a previous study, we reported the results of a survey of software engineering practices in the Costa Rican industry. To make a more in-depth analysis of the specific software testing practices among practitioners, we replicated a previous survey conducted in South America. Our objective was to characterize the state of the practice based on practitioners' use and perceived importance of those practices. This survey evaluated 42 testing practices grouped in three categories: processes, activities, and tools. A total of 92 practitioners responded to the survey. The participants indicated that: (1) tasks for recording the results of tests, documentation of test procedures and cases, and re-execution of tests when the software is modified are useful and important for software testing practitioners. (2) Acceptance and system testing are the two most useful and important testing types. (3) Tools for recording defects and the effort to fix them (bug tracking) and the availability of a test database for reuse are useful and important. Regarding the use and implementation of practices, the participants stated that (4) Planning and designing of software testing before coding and evaluating the quality of test artifacts are not a regular practice. (5) There is a lack of measurement of defect density and test coverage in the industry; and (6) tools for automatic generation of test cases and for estimating testing effort are rarely used. This study gave us a first glance at the state of the practice in software testing in a thriving and very dynamic industry that currently employs most of our computer science professionals. The benefits are twofold: for academia, it provides us with a road map to revise our academic offer, and for practitioners, it provides them with a first set of data to benchmark their practices. [ABSTRACT FROM AUTHOR]

The development of a reliable and efficient software application system requires a competent software architecture which can attune to any design improvement opportunity in the early stages of software architectural design. An Architectural Description Language provides a description of all the component elements and their interactions. The proposed model determines all possible ways of connecting the components and connectors, after eliminating the transitive and symmetric conflicts among the connections, followed by the generation of the software architectural specification. An estimate on the maximum number of architectural specifications generated for a given number of components has been carried out. The syntax for specifying the components and the connectors has been formulated. The model proposed in the current work is generic and it will significantly help a software architect in building reliable, efficient and flexible software architecture, for any valid combination of components and connectors. It has been successfully tested for two prototype applications that involve processing of images and documents. [ABSTRACT FROM AUTHOR]

Three key drivers of change in the world of software are identified, and their impact on a range of software engineering research is assessed. The rise of agile approaches to software development adds further pressure for software process research to develop and evolve processes that are supportive of change while meeting the most stringent needs of society. Two examples of successful process evolution, aimed at highly regulated industries, are outlined as pointers to the future direction of Software Process Research. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In the early days of digital computing (1929-1949), the computation of a list of primes was often used as a test or demonstration problem. The idea to use electronic machinery to produce a list of primes originated with Derrick H. Lehmer, but it was later taken up by Claude E. Shannon and recurred as computations on the ENIAC and EDSAC. The historical sequence of computing prime numbers is marked by a turn from dedicated hardware to writing and debugging software, although special-purpose sieve machinery was still built and used after 1949. [ABSTRACT FROM PUBLISHER]

Probabilistic models are commonly used to evaluate quality attributes, such as reliability, availability, safety and performance of software-intensive systems. The accuracy of the evaluation results depends on a number of system properties which have to be estimated, such as environmental factors or system usage. Researchers have tackled this problem by including uncertainties in the probabilistic models and solving them analytically or with simulations. The input parameters are commonly assumed to be normally distributed. Accordingly, reporting the mean and variances of the resulting attributes is usually considered sufficient. However, many of the uncertain factors do not follow normal distributions, and analytical methods to derive objective uncertainties become impractical with increasing complexity of the probabilistic models. In this work, we introduce a simulation-based approach which uses Discrete Time Markov Chains and probabilistic model checking to accommodate a diverse set of parameter range distributions. The number of simulation runs automatically regulates to the desired significance level and reports the desired percentiles of the values which ultimately characterises a specific quality attribute of the system. We include a case study which illustrates the flexibility of this approach using the evaluation of several probabilistic properties. [ABSTRACT FROM AUTHOR]