240,797 research outputs found

    UML to XML-Schema Transformation: a Case Study in Managing Alternative Model Transformations in MDA

    Get PDF
    In a Model Driven Architecture (MDA) software development process, models are\ud repeatedly transformed to other models in order to finally achieve a set of models with enough details to implement a system. Generally, there are multiple ways to transform one model into another model. Alternative target models differ in their quality properties and the selection of a particular model is determined on the basis of specific requirements. Software engineers must be able to identify, compare and select the appropriate transformations within the given set of requirements. The current transformation languages used for describing and executing model transformations only provide means to specify the transformations but do not help to identify and select from the alternative transformations. In this paper we propose a process and a set of techniques for constructing a transformation space for a given transformation problem. The process uses a source model, its meta-model and the meta-model of the target as input and generates a transformation space. Every element in that space represents a transformation that produces a result that is an instance of the target meta-model. The requirements that must be fulfilled by the result are captured and represented in a quality model. We explain our approach using an illustrative example for transforming a platform independent model expressed in UML into platform specific models that represent XML schemas. A particular quality model of extensibility is presented in the paper

    Characterizing and evaluating the quality of software process modeling language: Comparison of ten representative model-based languages

    Get PDF
    Software organizations are very conscious that deployments of well-defined software processes improve software product development and its quality. Over last decade, many Software Process Modeling Languages (SPMLs) have been proposed to describe and manage software processes. However, each one presents advantages and disadvantages. The main challenge for an organization is to choose the best and most suitable SPML to meet its requirements. This paper proposes a Quality Model (QM) which has been defined conforms to QuEF (Quality Evaluation Framework). This QM allows to compare model-based SPMLs and it could be used by organizations to choose the most useful model-based SPML for their particular requirements. This paper also instances our QM to evaluate and compare 10 representative SPMLs of the various alternative approaches (metamodel-level approaches; SPML based on UML and approaches based on standards). Finally, this paper concludes there are many model-based proposals for SPM, but it is very difficult to establish with could be the commitment to follow. Some non-considered aspects until now have been identified (e.g., validation within enterprise environments, friendly support tools, mechanisms to carry out continuous improvement, mechanisms to establish business rules and elements for software process orchestrating).Ministerio de EconomĂ­a y Competitividad TIN2016-76956-C3-2-R (POLOLAS

    The transformational implementation of JSD process specifications via finite automata representation

    Get PDF
    Conventional structured methods of software engineering are often based on the use of functional decomposition coupled with the Waterfall development process model. This approach is argued to be inadequate for coping with the evolutionary nature of large software systems. Alternative development paradigms, including the operational paradigm and the transformational paradigm, have been proposed to address the inadequacies of this conventional view of software developement, and these are reviewed. JSD is presented as an example of an operational approach to software engineering, and is contrasted with other well documented examples. The thesis shows how aspects of JSD can be characterised with reference to formal language theory and automata theory. In particular, it is noted that Jackson structure diagrams are equivalent to regular expressions and can be thought of as specifying corresponding finite automata. The thesis discusses the automatic transformation of structure diagrams into finite automata using an algorithm adapted from compiler theory, and then extends the technique to deal with areas of JSD which are not strictly formalisable in terms of regular languages. In particular, an elegant and novel method for dealing with so called recognition (or parsing) difficulties is described,. Various applications of the extended technique are described. They include a new method of automatically implementing the dismemberment transformation; an efficient way of implementing inversion in languages lacking a goto-statement; and a new in-the-large implementation strategy

    Time for Addressing Software Security Issues: Prediction Models and Impacting Factors

    Get PDF
    Finding and fixing software vulnerabilities have become a major struggle for most software development companies. While generally without alternative, such fixing efforts are a major cost factor, which is why companies have a vital interest in focusing their secure software development activities such that they obtain an optimal return on this investment. We investigate, in this paper, quantitatively the major factors that impact the time it takes to fix a given security issue based on data collected automatically within SAP’s secure development process, and we show how the issue fix time could be used to monitor the fixing process. We use three machine learning methods and evaluate their predictive power in predicting the time to fix issues. Interestingly, the models indicate that vulnerability type has less dominant impact on issue fix time than previously believed. The time it takes to fix an issue instead seems much more related to the component in which the potential vulnerability resides, the project related to the issue, the development groups that address the issue, and the closeness of the software release date. This indicates that the software structure, the fixing processes, and the development groups are the dominant factors that impact the time spent to address security issues. SAP can use the models to implement a continuous improvement of its secure software development process and to measure the impact of individual improvements. The development teams at SAP develop different types of software, adopt different internal development processes, use different programming languages and platforms, and are located in different cities and countries. Other organizations, may use the results—with precaution—and be learning organizations

    Safe software development for a video-based train detection system in accordance with EN 50128

    Get PDF
    Diese Studienarbeit gibt einen Überblick ĂŒber ausgewĂ€hlte Teile des Softwareentwicklungsprozesses fĂŒr sicherheitsrelevante Applikationen am Beispiel eines videobasierten Zugerkennungssystems. Eine IP-Kamera und ein externer Bildverarbeitungscomputer wurden dazu mit einer speziell entworfenen, verteilten Software ausgestattet. Die in Ada und C geschriebenen Teile kommunizieren dabei ĂŒber ein dediziertes, UDP-basiertes Netzwerkprotokoll. Beide Programme wurden intensiv anhand verschiedener Techniken analysiert, die in der Norm EN 50128 festgelegt sind, welche sich speziell an Software fĂŒr Eisenbahnsteuerungs- und ĂŒberwachungssysteme richtet. Eine an der Norm orientierte Struktur mit Verweisen auf die diskutierten Techniken zu Beginn eines jeden Abschnitts erlaubt einen schnellen Vergleich mit den originalen Anforderungen des Normtexts. Zusammenfassend haben sich die Techniken bis auf wenige Ausnahmen als sehr geeignet fĂŒr die praktische Entwicklung von sicherer Software erwiesen. Allerdings entbindet die Norm durch ihre teils sehr abstrakten Anforderungen das am Projekt beteiligte Personal in keinster Weise von seiner individuellen Verantwortung. Entsprechend sind die hier vorgestellten Techniken fĂŒr andere Projekte nicht ohne Anpassungen zu ĂŒbernehmen.:1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 1.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 1.2 Description of the problem . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 1.3 Real-time constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 1.4 Safety requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2 Implementation details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.1 Camera type and output format . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.2 Transfer Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.3 Real-world constrains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2.4 Train Detection Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 3 EN 50128 requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 3.1 Software architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3.1.1 Defensive Programming . . . . . . . . . . . . . . . . . . . . . . . 20 3.1.2 Fully Defined Interface . . . . . . . . . . . . . . . . . . . . . . . . 21 3.1.3 Structured Methodology . . . . . . . . . . . . . . . . . . . . . . . 21 3.1.4 Error Detecting and Correcting Codes . . . . . . . . . . . . . . . . 29 3.1.5 Modelling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 3.1.6 Alternative optionally required measures . . . . . . . . . . . . . . 34 3.2 Software Design and Implementation . . . . . . . . . . . . . . . . . . . . . 35 3.2.1 Structured Methodology . . . . . . . . . . . . . . . . . . . . . . . 35 3.2.2 Modular Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 3.2.3 Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 3.2.4 Design and Coding Standards . . . . . . . . . . . . . . . . . . . . 39 3.2.5 Strongly Typed Programming Languages . . . . . . . . . . . . . . 41 3.2.6 Alternative optionally required measures . . . . . . . . . . . . . . 44 3.3 Unit Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 4 Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48This paper intends to give an overview of selected parts of the software development process for safety-relevant applications using the example of a video-based train detection. An IP-camera and an external image processing computer were equipped with a custom-built, distributed software system. Written in Ada and C, the system parts communicate via a dedicated UDP-based protocol. Both programs were subject to intense analysis according to measures laid down in the EN 50128 standard specifically targeted at software for railway control and protection systems. Preceding each section, a structure resembling the standard document with references to the discussed measures allows for easy comparison with the original requirements of EN 50128. In summary, the techniques have proven to be very suitable for practical safe software development in all but very few edge-cases. However, the highly abstract descriptive level of the standard requires the staff involved to accept an enormous personal responsibility throughout the entire development process. The specific measures carried out for this project may therefore not be equally applicable elsewhere.:1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 1.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 1.2 Description of the problem . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 1.3 Real-time constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 1.4 Safety requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2 Implementation details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.1 Camera type and output format . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.2 Transfer Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.3 Real-world constrains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2.4 Train Detection Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 3 EN 50128 requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 3.1 Software architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3.1.1 Defensive Programming . . . . . . . . . . . . . . . . . . . . . . . 20 3.1.2 Fully Defined Interface . . . . . . . . . . . . . . . . . . . . . . . . 21 3.1.3 Structured Methodology . . . . . . . . . . . . . . . . . . . . . . . 21 3.1.4 Error Detecting and Correcting Codes . . . . . . . . . . . . . . . . 29 3.1.5 Modelling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 3.1.6 Alternative optionally required measures . . . . . . . . . . . . . . 34 3.2 Software Design and Implementation . . . . . . . . . . . . . . . . . . . . . 35 3.2.1 Structured Methodology . . . . . . . . . . . . . . . . . . . . . . . 35 3.2.2 Modular Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 3.2.3 Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 3.2.4 Design and Coding Standards . . . . . . . . . . . . . . . . . . . . 39 3.2.5 Strongly Typed Programming Languages . . . . . . . . . . . . . . 41 3.2.6 Alternative optionally required measures . . . . . . . . . . . . . . 44 3.3 Unit Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 4 Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

    Lightweight specification and analysis of dynamic systems with rich configurations

    Get PDF
    Model-checking is increasingly popular in the early phases of the software development process. To establish the correctness of a software design one must usually verify both structural and behavioral(or temporal) properties. Unfortunately, most specification languages, and accompanying model-checkers, excel only in analyzing either one or the other kind. This limits their ability to verify dynamic systems with rich configurations: systems whose state space is characterized by rich structural properties, but whose evolution is also expected to satisfy certain temporal properties.To address this problem, we first propose Electrum, an extension of the Alloy specification language with temporal logic operators, where both rich configurations and expressive temporal properties can easily be de fined. Two alternative model-checking techniques are then proposed, one bounded and the other unbounded, to verify systems expressed in this language, namely to verify that every desirable temporal property holds for every possible configuration.ERDF - European Regional Development Fund()info:eu-repo/semantics/publishedVersio

    Graphical modelling language for spycifying concurrency based on CSP

    Get PDF
    Introduced in this (shortened) paper is a graphical modelling language for specifying concurrency in software designs. The language notations are derived from CSP and the resulting designs form CSP diagrams. The notations reflect both data-flow and control-flow aspects of concurrent software architectures. These designs can automatically be described by CSP algebraic expressions that can be used for formal analysis. The designer does not have to be aware of the underlying mathematics. The techniques and rules presented provide guidance to the development of concurrent software architectures. One can detect and reason about compositional conflicts (errors in design), potential deadlocks (errors at run-time), and priority inversion problems (performance burden) at a high level of abstraction. The CSP diagram collaborates with objectoriented modelling languages and structured methods

    Pattern languages in HCI: A critical review

    Get PDF
    This article presents a critical review of patterns and pattern languages in human-computer interaction (HCI). In recent years, patterns and pattern languages have received considerable attention in HCI for their potential as a means for developing and communicating information and knowledge to support good design. This review examines the background to patterns and pattern languages in HCI, and seeks to locate pattern languages in relation to other approaches to interaction design. The review explores four key issues: What is a pattern? What is a pattern language? How are patterns and pattern languages used? and How are values reflected in the pattern-based approach to design? Following on from the review, a future research agenda is proposed for patterns and pattern languages in HCI

    Iterative criteria-based approach to engineering the requirements of software development methodologies

    Get PDF
    Software engineering endeavours are typically based on and governed by the requirements of the target software; requirements identification is therefore an integral part of software development methodologies. Similarly, engineering a software development methodology (SDM) involves the identification of the requirements of the target methodology. Methodology engineering approaches pay special attention to this issue; however, they make little use of existing methodologies as sources of insight into methodology requirements. The authors propose an iterative method for eliciting and specifying the requirements of a SDM using existing methodologies as supplementary resources. The method is performed as the analysis phase of a methodology engineering process aimed at the ultimate design and implementation of a target methodology. An initial set of requirements is first identified through analysing the characteristics of the development situation at hand and/or via delineating the general features desirable in the target methodology. These initial requirements are used as evaluation criteria; refined through iterative application to a select set of relevant methodologies. The finalised criteria highlight the qualities that the target methodology is expected to possess, and are therefore used as a basis for de. ning the final set of requirements. In an example, the authors demonstrate how the proposed elicitation process can be used for identifying the requirements of a general object-oriented SDM. Owing to its basis in knowledge gained from existing methodologies and practices, the proposed method can help methodology engineers produce a set of requirements that is not only more complete in span, but also more concrete and rigorous
    • 

    corecore