Decision-making coordination and efficient reasoning techniques for feature-based configuration

Software Product Lines is a contemporary approach to software development that exploits the similarities and differences within a family of systems in a particular domain of interest in order to provide a common infrastructure for deriving members of this family in a timely fashion, with high-quality standards, and at lower costs.In Software Product Lines, feature-based product configuration is the process of selecting the desired features for a given software product from a repository of features called a feature model. This process is usually carried out collaboratively by people with distinct skills and interests called stakeholders. Collaboration benefits stakeholders by allowing them to directly intervene in the configuration process. However, collaboration also raises an important side effect, i.e., the need of stakeholders to cope with decision conflicts. Conflicts arise when decisions that are locally consistent cannot be applied globally because they violate one or more constraints in the feature model.Unfortunately, current product configuration systems are typically single-user-based in the sense that they do not provide means to coordinate concurrent decision-making on the feature model. As a consequence, configuration is carried out by a single person that is in charge of representing the interests of all stakeholders and managing decision conflicts on their own. This results in an error-prone and time-consuming process that requires past decisions to be revisited continuously either to correct misinterpreted stakeholder requirements or to handle decision conflicts. Yet another challenging issue related to configuration problems is the typically high computational cost of configuration algorithms. In fact, these algorithms frequently fall into the category of NP-hard and thus can become intractable in practice.In this paper, our goal is two-fold. First, we revisit our work on Collaborative Product Configuration (CPC) in which we proposed an approach to describe and validate collaborative configuration scenarios. We discuss how collaborative configuration can be described in terms of a workflow-like plan that safely guides stakeholders during the configuration process. Second, we propose a preliminary set of reasoning algorithms tailored to the feature modelling domain that can be used to provide automated support for product configuration. In addition, we compare empirically the performance of the proposed algorithms to that of a general-purpose solution. We hope that the insights provided in this paper will encourage other researchers to develop new algorithms in the near future.     

基于多视图的特征模型定制(英文)

特征模型是捕获特定领域可复用软件需求的一种重要技术手段。对特征模型的复用通常采用定制的方式,通过定制使其适应领域内不同系统的特定需求。特征模型定制的一个难点在于定制过程往往涉及众多的利益相关者,而这些利益相关者的关注点各有不同。由于特征模型是针对整个领域的需求而组织的,特定利益相关者的关注点可能散布在整个特征模型中且可能与其他利益相关者的关注点相互交织,这为特定利益相关者的定制工作带来一定的困难。为此,文章提出一种基于多视图的特征模型定制方法,针对不同的利益相关者将其所关注的散布在整个特征模型中的信息聚类到不同的视图中,并提供一种约束一致性维护机制,方便相应的利益相关者的定制活动。     

Supporting distributed product configuration by integrating heterogeneous variability modeling approaches

ContextIn industrial settings products are developed by more than one organization. Software vendors and suppliers commonly typically maintain their own product lines, which contribute to a larger (multi) product line or software ecosystem. It is unrealistic to assume that the participating organizations will agree on using a specific variability modeling technique—they will rather use different approaches and tools to manage the variability of their systems.ObjectiveWe aim to support product configuration in software ecosystems based on several variability models with different semantics that have been created using different notations.MethodWe present an integrative approach that provides a unified perspective to users configuring products in multi product line environments, regardless of the different modeling methods and tools used internally. We also present a technical infrastructure and a prototype implementation based on web services.ResultsWe show the feasibility of the approach and its implementation by using it with the three most widespread types of variability modeling approaches in the product line community, i.e., feature-based, OVM-style, and decision-oriented modeling. To demonstrate the feasibility and flexibility of our approach, we present an example derived from industrial experience in enterprise resource planning. We further applied the approach to support the configuration of privacy settings in the Android ecosystem based on multiple variability models. We also evaluated the performance of different model enactment strategies used in our approach.ConclusionsTools and techniques allowing stakeholders to handle variability in a uniform manner can considerably foster the initiation and growth of software ecosystems from the perspective of software reuse and configuration.     

Cybercrime: Understanding and addressing the concerns of stakeholders

Cybercrime and cybercriminal activities continue to impact communities as the steady growth of electronic information systems enables more online business. The collective views of sixty-six computer users and organizations, that have an exposure to cybercrime, were analyzed using concept analysis and mapping techniques in order to identify the major issues and areas of concern, and provide useful advice. The findings of the study show that a range of computing stakeholders have genuine concerns about the frequency of information security breaches and malware incursions (including the emergence of dangerous security and detection avoiding malware), the need for e-security awareness and education, the roles played by law and law enforcement, and the installation of current security software and systems. While not necessarily criminal in nature, some stakeholders also expressed deep concerns over the use of computers for cyberbullying, particularly where younger and school aged users are involved. The government’s future directions and recommendations for the technical and administrative management of cybercriminal activity were generally observed to be consistent with stakeholder concerns, with some users also taking practical steps to reduce cybercrime risks.     

Dynamic decision models for staged software product line configuration

Software product line engineering practices offer desirable characteristics such as rapid product development, reduced time-to-market, and more affordable development costs as a result of systematic representation of the variabilities of a domain of discourse that leads to methodical reuse of software assets. The development lifecycle of a product line consists of two main phases: domain engineering, which deals with the understanding and formally modeling of the target domain, and application engineering that is concerned with the configuration of a product line into one concrete product based on the preferences and requirements of the stakeholders. The work presented in this paper focuses on the application engineering phase and builds both the theoretical and technological tools to assist the stakeholders in (a) understanding the complex interactions of the features of a product line; (b) eliciting the utility of each feature for the stakeholders and hence exposing the stakeholders’ otherwise implicit preferences in a way that they can more easily make decisions; and (c) dynamically building a decision model through interaction with the stakeholders and by considering the structural characteristics of software product line feature models, which will guide the stakeholders through the product configuration process. Initial exploratory empirical experiments that we have performed show that our proposed approach for helping stakeholders understand their feature preferences and its associated staged feature model configuration process is able to positively impact the quality of the end results of the application engineering process within the context of the limited number of participants. In addition, it has been observed that the offered tooling support is able to ease the staged feature model configuration process.     

Viewpoints of DSP software and service architectures

The software architecture of a future mobile telecommunication system consists of three main parts: system infrastructure services, middleware services and application services. Infrastructure services provide access technologies and networking services for the middleware services that again provide richer capabilities for wireless applications through mobile Internet. Architecture describes the organization of software systems, components, their internal relationships and connections to the environment. Reusing architectural structures benefits companies, because the architecture is a pivotal part of any system, and a costly one to construct. Architecture is documented and reused through architectural views that describe identified stakeholders and concerns, e.g. the purpose of a system, and the feasibility of constructing, deploying, evolving and maintaining it. Views conform to special viewpoints defined for the domain. This paper describes the viewpoints selected for developing the architecture of middleware services and digital signal processing software and provides a general framework for comparing viewpoints. Comparison and analysis of the defined viewpoints show that domain and system size are the dominant issues to be considered when architectural viewpoints are being selected.     

Toward automated feature model configuration with optimizing non-functional requirements

ContextA software product line is a family of software systems that share some common features but also have significant variabilities. A feature model is a variability modeling artifact, which represents differences among software products with respect to the variability relationships among their features. Having a feature model along with a reference model developed in the domain engineering lifecycle, a concrete product of the family is derived by binding the variation points in the feature model (called configuration process) and by instantiating the reference model.ObjectiveIn this work we address the feature model configuration problem and propose a framework to automatically select suitable features that satisfy both the functional and non-functional preferences and constraints of stakeholders. Additionally, interdependencies between various non-functional properties are taken into account in the framework.MethodThe proposed framework combines Analytical Hierarchy Process (AHP) and Fuzzy Cognitive Maps (FCM) to compute the non-functional properties weights based on stakeholders’ preferences and interdependencies between non-functional properties. Afterwards, Hierarchical Task Network (HTN) planning is applied to find the optimal feature model configuration.ResultOur approach improves state-of-art of feature model configuration by considering positive or negative impacts of the features on non-functional properties, the stakeholders’ preferences, and non-functional interdependencies. The approach presented in this paper extends earlier work presented in [1] from several distinct perspectives including mechanisms handling interdependencies between non-functional properties, proposing a novel tooling architecture, and offering visualization and interaction techniques for representing functional and non-functional aspects of feature models.Conclusionour experiments show the scalability of our configuration approach when considering both functional and non-functional requirements of stakeholders.     

Shimba—an environment for reverse engineering Java software systems

Shimba is a reverse engineering environment to support the understanding of Java software systems. Shimba integrates the Rigi and SCED tools to analyze and visualize the static and dynamic aspects of a subject system. The static software artifacts and their dependencies are extracted from Java byte code and viewed as directed graphs using the Rigi reverse engineering environment. The run‐time information is generated by running the target software under a customized SDK debugger. The generated information is viewed as sequence diagrams using the SCED tool. In SCED, statechart diagrams can be synthesized automatically from sequence diagrams, allowing the user to investigate the overall run‐time behavior of objects in the target system. Shimba provides facilities to manage the different diagrams and to trace artifacts and relations across views. In Shimba, SCED sequence diagrams are used to slice the static dependency graphs produced by Rigi. In turn, Rigi graphs are used to guide the generation of SCED sequence diagrams and to raise their level of abstraction. We show how the information exchange among the views enables goal‐driven reverse engineering tasks and aids the overall understanding of the target software system. The FUJABA software system serves as a case study to illustrate and validate the Shimba reverse engineering environment. Copyright © 2001 John Wiley & Sons, Ltd.     

Automating the product derivation process of multi-agent systems product lines

Agent-oriented software engineering and software product lines are two promising software engineering techniques. Recent research work has been exploring their integration, namely multi-agent systems product lines (MAS-PLs), to promote reuse and variability management in the context of complex software systems. However, current product derivation approaches do not provide specific mechanisms to deal with MAS-PLs. This is essential because they typically encompass several concerns (e.g., trust, coordination, transaction, state persistence) that are constructed on the basis of heterogeneous technologies (e.g., object-oriented frameworks and platforms). In this paper, we propose the use of multi-level models to support the configuration knowledge specification and automatic product derivation of MAS-PLs. Our approach provides an agent-specific architecture model that uses abstractions and instantiation rules that are relevant to this application domain. In order to evaluate the feasibility and effectiveness of the proposed approach, we have implemented it as an extension of an existing product derivation tool, called GenArch. The approach has also been evaluated through the automatic instantiation of two MAS-PLs, demonstrating its potential and benefits to product derivation and configuration knowledge specification.     

Visualisation of Sensor Data from Animal Movement

A new area of biological research is identifying and grouping patterns of behaviour in wild animals by analysing data obtained through the attachment of tri-axial accelerometers. As these recording devices become smaller and less expensive their use has increased. Currently acceleration data are visualised as 2D time series plots, and analyses are based on summary statistics and the application of Fourier transforms. We develop alternate visualisations of this data so as to analyse, explore and present new patterns of animal behaviour. Our visualisations include interactive spherical scatterplots, spherical histograms, clustering methods, and feature-based state diagrams of the data. We study the application of these visualisation methods to accelerometry data from animal movement. The reaction of biologists to these visualisations is also reported.     

Enhancing collaborative synchronous UML modelling with fine-grained versioning of software artefacts

Software development teams are composed of people with different knowledge and skills, who contribute to a project from often widely dispersed locations. Software development in geographically distributed environments creates software engineering challenges due to the interaction among members of distributed teams and the management of consistency and concurrency among project artefacts. In this paper, we propose Synchronous collaborative modelling Tool Enhanced with VErsioning management (STEVE) a collaborative tool supporting distributed Unified Modelling Language (UML) modelling of software systems. The tool provides a communication infrastructure enabling the concurrent editing of the same UML diagram at the same time by distributed developers. Complex UML diagrams are decomposed and managed in a fine-grained hierarchy of sub-artefacts, thus providing change and configuration management functionalities for both the diagram and the graphical objects. Thus, software predefined diagram components can be consistently reused and shared across different diagrams of a given project.     

Generating systems from multiple sketched models

Diagrams are often used to model complex systems: in many cases several different types of diagrams are used to model different aspects of the system. These diagrams, perhaps from multiple stakeholders of different specialties, must be combined to achieve a full abstract representation of the system. Many CAD tools offer multi-diagram integration; however, sketch-based diagramming tools are yet to tackle this difficult integration problem. We extend the diagram sketching tool InkKit to combine software engineering sketches of different types. Our extensions support software design processes by providing a sketch-based approach that allows the iterative creation of multiple outputs interacting with one another from the inter-linked models. We demonstrate that InkKit can generate a functional system consisting of a user interface with processes to submit and retrieve data from a database from sketched user interfaces designs and sketched entity relationship diagrams.     

Support software for the development of programmable logic controller applications

Enhancements to the software aids, used for the development of Programmable Logic Controller programs, are proposed in this work. A possible architecture of the software realizing these enhancements and the language constructs required for its configuration to a specific application are also presented. Based on this architecture, experimental software aids have been developed to demonstrate that it is quite feasible to provide the major services considered in this proposal. These services allow the program developer to emulate the dynamic operation of a specific programmable controller to alternative scenarios of input variations and relationships over a defined time horizon, and configure displays of graphics and timing diagrams which may assist him in following up and testing the program execution.     

Software effort models for early estimation of process controlapplications

Models are developed to estimate lines of code and function counts directly from user application features of process control systems early in the software development lifecycle. Since the application features are known with reasonable degree of confidence during early stages of development, it is possible to extend the use of the constructive cost model (COCOMO) and function-points-based approach for early software cost estimation. Alternative feature-based models that estimate size and effort using application features and productivity factors are developed. The feature-based models have been shown to estimate software effort with the least error     

基于特征的反求工程建模系统RE-SOFT

RE-SOFT作为一个专业化的反求工程建模软件在业界拥有较高的知名度，其许多核心技术独具特色．介绍了该软件的整体架构、主要功能和若干关键技术．通过对数据预处理、特征提取、特征重建和编辑中的一些核心技术的介绍，展示了反求工程领域的最新研究成果．叶片反求建模的应用分析表明，应用该系统进行反求建模可以获得完整特征表达的理想CAD模型．最后总结了RE-SOFT的主要特色，并给出了今后反求工程领域的主要研究方向．     

Speaking Truth to Power

Whenever the author conducts an architectural assessment for software development projects, he endeavors to speak truth to power: those with true power never fear the truth. Sam Guckenheimer has observed that in software code there is truth. Code represents the stark reality of a software development organization's labor. There is also truth to be found in a system's architecture. Every system's architecture is molded by the forces that swirl around it, and the collective concerns of all the stakeholders represent the most dynamic forces shaping a system. The software development organization's unique task is to address all the essential concerns of all the important stakeholders and to ensure that they aren't blindsided by unexpected problems and stakeholders. This is why employing a process that incrementally and iteratively grows a system's architecture through the regular release of testable executables is so important. Such a process lets the software team engage the right stakeholders at the right time and to make the right decisions, neither too early nor too late. In creating a software-intensive system that's both relevant and beautiful, every stakeholder, no matter how close or how far from the code, deserves the truth     

Mining early aspects based on syntactical and dependency analyses

Aspect-Oriented Requirements Engineering focuses on the identification and modularisation of crosscutting concerns at early stages. There are different approaches in the requirements engineering community to deal with crosscutting concerns, introducing the benefits of the application of aspect-oriented approaches at these early stages of development. However, most of these approaches rely on the use of Natural Language Processing techniques for aspect identification in textual documents and thus, they lack a unified process that generalises its application to other requirements artefacts such as use case diagrams or viewpoints. In this paper, we propose a process for mining early aspects, i.e. identifying crosscutting concerns at the requirements level. This process is based on a crosscutting pattern where two different domains are related. These two different domains may represent different artefacts of the requirements analysis such as text and use cases or concerns and use cases. The process uses syntactical and dependency based analyses to automatically identify crosscutting concerns at the requirements level. Validation of the process is illustrated by applying it to several systems and showing a comparison with other early aspects tools. A set of aspect-oriented metrics is also used to show this validation.