User requirements modeling and analysis of software-intensive systems

The increasing complexity of software systems makes Requirements Engineering activities both more important and more difficult. This article is about user requirements development, mainly the activities of documenting and analyzing user requirements for software-intensive systems. These are modeling activities that are useful for further Requirements Engineering activities. Current techniques for requirements modeling present a number of problems and limitations. Based on these shortcomings, a list of requirements for requirements modeling languages is proposed. The proposal of this article is to show how some extensions to SysML diagrams and tables can fulfill most of these requirements. The approach is illustrated by a list of user requirements for a Road Traffic Management System.     

Evaluating performance in the development of software-intensive products

ContextOrganizational performance measurements in software product development have received a lot of attention in the literature. Still, there is a general discontent regarding the way performance is evaluated in practice, with few studies really focusing on why this is the case. In this paper research focusing on the context of developing software-intensive products in large established multi-national organizations is reported on.ObjectiveThe purpose of this research is to investigate performance measurement practices related to software product development activities. More specifically, focus is on exploring how managers engaged in software product development activities perceive and evaluate performance in large organizations from a managerial perspective.MethodThe research approach pursued in this research consist of exploratory multiple case studies. Data is collected mainly through 54 interviews in five case studies in large international organizations developing software-intensive products in Sweden. Focused group interviews with senior managers from eight companies have also been used in the data collection.ResultsThe results of this research indicate that managers within software product development in general are dissatisfied with their current way of evaluating performance. Performance measurements and the perception of performance are today focused on cost, time, and quality, i.e. what is easily measurable and not necessarily what is important. The dimensions of value creation and learning are missing. Moreover, measurements tend to be result oriented, rather than process oriented, making it difficult to integrate these measurements in the management practices.ConclusionManagers that are dissatisfied with their performance measurement system and want to improve the current situation should not start by focusing on the current measurements directly; instead they should focus on how the organization perceives performance and how important performance criteria are being developed. By developing relevant performance criteria the first step in developing an effective performance measurement system is made. Moreover, it is concluded that manager’s perception of performance is affected by the currently used measurements, hence limiting the scope of the performance criteria. Thus, a change in the way managers perceive performance is necessary before there can be any changes in the way performance is evaluated.     

CONFIDDENT: A model-driven consistent and non-redundant layer-3 firewall ACL design, development and maintenance framework

Design, development, and maintenance of firewall ACLs are very hard and error-prone tasks. Two of the reasons for these difficulties are, on the one hand, the big gap that exists between the access control requirements and the complex and heterogeneous firewall platforms and languages and, on the other hand, the absence of ACL design, development and maintenance environments that integrate inconsistency and redundancy diagnosis. The use of modelling languages surely helps but, although several ones have been proposed, none of them has been widely adopted by industry due to a combination of factors: high complexity, unsupported firewall important features, no integrated model validation stages, etc. In this paper, CONFIDDENT, a model-driven design, development and maintenance framework for layer-3 firewall ACLs is proposed. The framework includes different modelling stages at different abstraction levels. In this way, non-experienced administrators can use more abstract models while experienced ones can refine them to include platform-specific features. CONFIDDENT includes different model diagnosis stages where the administrators can check the inconsistencies and redundancies of their models before the automatic generation of the ACL to one of the many of the market-leader firewall platforms currently supported.     

A top-down strategy to reverse architecting execution views for a large and complex software-intensive system: An experience report

This article is an experience report about the application of a top-down strategy to use and embed an architecture reconstruction approach in the incremental software development process of the Philips MRI scanner, a representative large and complex software-intensive system. The approach is an iterative process to construct execution views without being overwhelmed by the system size and complexity. An execution view contains architectural information that describes what the software of a software-intensive system does at runtime and how it does this. The application of the strategy is illustrated with a case study, the construction of an up-to-date execution view for the start-up process of the Philips MRI scanner. The construction of this view helped the development organization to quickly reduce about 30% the start-up time of the scanner, and set up a new system benchmark for assuring the system performance through future evolution steps. The report provides detailed information about the application of the top-down strategy, including how it supports top-down analysis, communication within the development organization, and the aspects that influence the use of the top-down strategy in other contexts.     

Aspect-oriented model-driven skeleton code generation: A graph-based transformation approach

Model-driven code generation has been investigated in traditional and object-oriented design paradigms; significant progress has been made. It offers many advantages including the rapid development of high quality code. Errors are reduced and the consistency between the design and the code is retained, in comparison with a purely manual approach. Here, a model-driven code generation approach based on graph transformations for aspect-oriented development is proposed. The approach has two main transformation activities. The first activity transforms a visual (graphical) model of the design into a formal, text-based notation that can be readily processed. The graphical model is created by the software designer and uses a UML profile for aspect-oriented software (i.e., FDAF) to represent aspects and their components. XML is the target notation for this step; the transformation uses the XML meta-model to ensure that the output complies with the language. The second activity transforms the XML model into AspectJ source code. The transformation uses the AspectJ meta-model to ensure the output complies with the language. The transformations from the extended UML model to XML and from XML to AspectJ code are fully automated. The transformation algorithms are based on graph transformations; tool support has been developed. Key technical issues in the approach are discussed, including performance, the amount of code generated, correctness, and adaptability, in addition to a comparison of the proposal with existing alternative approaches. The approach has been validated on three example systems: a banking system, classroom scheduling system, and an insurance system. The banking system example is presented in the paper.     

A survey of timed automata for the development of real-time systems

Timed automata are a popular formalism to model real-time systems. They were introduced two decades ago to support formal verification. Since then they have also been used for other purposes and a large number of variants has been introduced to be able to deal with the many different kinds of requirements of real-time system development. This survey attempts to introduce a massive and complicated theoretical research area to a reader in an easy and compact manner. One objective of this paper is to inform a reader about the theoretical properties (or capabilities) of timed automata which are (or might be) useful for real-time model driven development. To achieve this goal, this paper presents a survey on semantics, decision problems, and variants of timed automata. The other objective of this paper is to inform a reader about the current state of the art of timed automata in practice. To achieve the second aim, this article presents a survey on timed automata’s implementability and tools.     

A human-in-the-loop manufacturing control architecture for the next generation of production systems

In recent years, the introduction of Industry 4.0 technologies in the manufacturing landscape promoted the development of smart factories characterised by relevant socio-technical interactions between humans and machines. In this context, understanding and modelling the role of humans turns out to be crucial to develop efficient manufacturing systems of the future. Grounding on previous researches in the field of Human-in-the-Loop and Human Cyber-Physical Systems, the paper aims at contributing to a deep reflection about human-machine interaction in the wider perspective of Social Human-in-the-Loop Cyber-Physical Production Systems, in which more agents collaborate and are socially connected. After presenting an evolution of manufacturing control organisations, an architecture to depict social interactions in smart factories is proposed. The proposed architecture contributes to the representation of different human roles in the smart factory and the exploration of both hierarchical and heterarchical data-driven decision-making processes in manufacturing.     

A text-based visual notation for the unit testing of model-driven tools

During the unit testing of model-driven tools, a large number of models and test classes needs to be managed and maintained. Typically, some of these artifacts are specified manually, some are generated automatically. Existing approaches to test management rely on the available visual and textual modeling notations. As these notations are not tailored to unit testing, distinct maintainability trade-offs arise.In this paper, we propose a notation that aims to combine the benefits of visual and text-based approaches. The notation is at the same time visual and text-based, as it uses ASCII characters to emulate the familiar graphical notations. In our evaluation based on real models, we identify problematic model shapes challenging the scalability our notation, while finding that it is well-suited to capture typical test models.     

Hybrid expert systems: A survey of current approaches and applications

This paper is a statistical analysis of hybrid expert system approaches and their applications but more specifically connectionist and neuro-fuzzy system oriented articles are considered. The current survey of hybrid expert systems is based on the classification of articles from 1988 to 2010. Present analysis includes 91 articles from related academic journals, conference proceedings and literature reviews. Our results show an increase in the number of recent publications which is an indication of gaining popularity on the part of hybrid expert systems. This increase in the articles is mainly in neuro-fuzzy and rough neural expert systems’ areas. We also observe that many new industrial applications are developed using hybrid expert systems recently.     

A model-driven process for the modernization of component-based systems

Software modernization is critical for organizations that need cost-effective solutions to deal with the rapid obsolescence of software and the increasing demand for new functionality. This paper presents the XIRUP modernization methodology, which proposes a highly iterative process, structured into four phases: preliminary evaluation, understanding, building and migration. This modernization process is feature-driven, component-based, focused on the early elicitation of key information, and relies on a model-driven approach with extensive use of experience from the previous projects. XIRUP has been defined in the European IST project MOMOCS, which has also built a suite of support tools. This paper introduces the process using a case study that illustrates its activities, related tools and results. The discussion highlights the specific characteristics of modernization projects and how a customized methodology can take advantage of them.     

无人系统视觉SLAM技术发展现状简析

视觉SLAM(visual SLAM,vSLAM)已成为无人系统在未知环境中实现全自主导航和环境感知不可或缺的重要组成部分.鉴于此,简要介绍vSLAM的发展历程和典型构成,总结两种前端位姿估计方法(特征法与直接法)和两种后端优化方法(非线性滤波与非线性优化)的典型代表及优缺点.在此基础上,依次按照耦合方式和后端优化方法...     

Development of service-oriented architectures using model-driven development: A mapping study

ContextModel-Driven Development (MDD) and Service-Oriented Architecture (SOA) are two challenging research areas in software engineering. MDD is about improving software development whilst SOA is a service-based conceptual development style, therefore investigating the available proposals in the literature to use MDD when developing SOA may be insightful. However, no studies have been found with this purpose.ObjectiveThis work aims at assessing the state of the art in MDD for SOA systems. It mainly focuses on: what are the characteristics of MDD approaches that support SOA; what types of SOA are supported; how do they handle non-functional requirements.MethodWe conducted a mapping study following a rigorous protocol. We identified the representative set of venues that should be included in the study. We applied a search string over the set of selected venues. As result, 129 papers were selected and analysed (both frequency analysis and correlation analysis) with respect to the defined classification criteria derived from the research questions. Threats to validity were identified and mitigated whenever possible.ResultsThe analysis allows us to answer the research questions. We highlight: (1) predominance of papers from Europe and written by researchers only; (2) predominance of top-down transformation in software development activities; (3) inexistence of consolidated methods; (4) significant percentage of works without tool support; (5) SOA systems and service compositions more targeted than single services and SOA enterprise systems; (6) limited use of metamodels; (7) very limited use of NFRs; and (8) limited application in real cases.ConclusionThis mapping study does not just provide the state of the art in the topic, but also identifies several issues that deserve investigation in the future, for instance the need of methods for activities other than software development (e.g., migration) or the need of conducting more real case studies.     

A model-driven and task-oriented method for the development of collaborative systems

Groupware systems are usually difficult to design when following traditional methodologies and approaches for single user systems. In this regard, model-driven approaches have been gaining attention in recent years. In accordance with this paradigm, we developed the SpacEclipse method in a previous work, which is a method for developing collaborative modeling groupware based on the plug-ins in the Eclipse Modeling Project. However, this method presents some deficiencies that we have tried to overcome in this work. In order to achieve this goal, we have chosen the CIAM methodology, which allows the modeling of collaboration, users, tasks, sessions and interactive issues and which is also supported by Eclipse-based tools. In this paper, we explain how the integration of CIAM elements in the SpacEclipse method has been carried out and resulted in a new method with its own methodological, conceptual and technological frameworks. To prove the validity of the method, we have applied it to a re-engineering process in the development of an existing tool.     

A multi-level model-driven regime for value-added tax compliance in ERP systems

As the economy becomes global and ICT-reliant, approaches practiced in enterprise software product development and enterprise resource planning (ERP) system implementation must cope with increasingly complex situations induced by contemporary supply chain and regulations. Compliance with regulations in the market is one aspect of the requirements that enterprise software must meet. Recent research of KPMG IT Advisory has confirmed that where little attention is being paid to the value-added tax (VAT) issues during large ERP projects, there is a higher VAT-risk exposure. In a design-oriented approach, we first identify the stakeholders and their interests in the VAT compliance of ERP systems. Enterprise architecture (EA) and model driven engineering in a multi-level perspective serve as the source of solution patterns. The efficient solution of compliance problems builds upon stakeholders utilizing a set of interdependent models and methods that are suitably allocated to the public and proprietary domains.     

A two visual systems approach to understanding voice and gestural interaction

It is important to consider the physiological and behavioral mechanisms that allow users to physically interact with virtual environments. Inspired by a neuroanatomical model of perception and action known as the two visual systems hypothesis, we conducted a study with two controlled experiments to compare four different kinds of spatial interaction: (1) voice-based input, (2) pointing with a visual cursor, (3) pointing without a visual cursor, and (4) pointing with a time-lagged visual cursor. Consistent with the two visual systems hypothesis, we found that voice-based input and pointing with a cursor were less robust to a display illusion known as the induced Roelofs effect than pointing without a cursor or even pointing with a lagged cursor. The implications of these findings are discussed, with an emphasis on how the two visual systems model can be used to understand the basis for voice and gestural interactions that support spatial target selection in large screen and immersive environments.     

混杂系统的研究进展

混杂系统理论和应用是近年来的一个研究热点．在介绍混杂系统概念的基础上，对混杂系统研究中的常用模型进行分类比较，并对混杂系统的性质分析和混杂控制设计中的主要内容和主要研究方法进行总结，最后对今后的研究方向做了总体展望。     

多采样率系统的辨识问题综述

在多率采样系统中, 采样间隔不均匀. 本文综述了文献中有关多率采样系统的数学模型, 如线性周期时变模型、频域模型和连续状态空间模型等. 同时对相应的辨识方法, 如提升、频域方法、子空间辨识方法等, 也进行了全面的综述. 对多率采样系统辨识中存在的一些问题, 包括辨识模型的选择、一致性问题、带约束条件的辨识方法和辨识收敛性等, 也作了深入的讨论.     

Scenario animation for visual behavior models: A generic approach

Visualizing and simulating formal models in a flexible way becomes increasingly important for the design of complex systems. With GenGED, a tool is available which automatically generates a visual environment to process (create, edit, check, simulate) visual models over a specified visual language. Both the specification of the language and the model manipulation are based on graph grammars. In this paper, we present the means to transform visual models into application oriented views, called scenario views. We show how a model is consistently transferred to a scenario views and animated there. The extension of GenGED concerning scenario animation is discussed.     

Automating test generation for discrete event oriented embedded systems

A method for the automatic generation of test scenarios from the behavioral requirements of a system is presented in this paper. The generated suite of test scenarios validates the system design or implementation against the requirements. The approach proposed here uses a requirements model and a set of four algorithms. The requirements model is an executable model of the proposed system defined in a deterministic state-based modeling formalism. Each action in the requirements model that changes the state of the model is identified with a unique requirement identifier. The scenario generation algorithms perform controlled simulations of the requirements model in order to generate a suite of test scenarios applicable for black box testing. Measurements of several metrics on the scenario generation algorithms have been collected using prototype tools.