Model-driven Engineering Technologies Research Articles

Fault localization in DSLTrans model transformations by combining symbolic execution and spectrum-based analysis

The verification of model transformations is important for realizing robust model-driven engineering technologies and quality-assured automation. Many approaches for checking properties of model transformations have been proposed. Most of them have focused on the effective and efficient detection of property violations by contract checking. However, there remains the fault localization step between identifying a failing contract for a transformation based on verification feedback and precisely identifying the faulty rules. While there exist fault localization approaches in the model transformation verification literature, these require the creation and maintenance of test cases, which imposes an additional burden on the developer. In this paper, we combine transformation verification based on symbolic execution with spectrum-based fault localization techniques for identifying the faulty rules in DSLTrans model transformations. This fault localization approach operates on the path condition output of symbolic transformation checkers instead of requiring a set of test input models. In particular, we introduce a workflow for running the symbolic execution of a model transformation, evaluating the defined contracts for satisfaction, and computing different measures for tracking the faulty rules. We evaluate the effectiveness of spectrum-based analysis techniques for tracking faulty rules and compare our approach to previous works. We evaluate our technique by introducing known mutations into five model transformations. Our results show that the best spectrum-based analysis techniques allow for effective fault localization, showing an average EXAM score below 0.30 (less than 30% of the transformation needs to be inspected). These techniques are also able to locate the faulty rule in the top-three ranked rules in 70% of all cases. The impact of the model transformation, the type of mutation and the type of contract on the results is discussed. Finally, we also investigate the cases where the technique does not work properly, including discussion of a potential pre-check to estimate the prospects of the technique for a certain transformation.

An EMOF-Compliant Abstract Syntax for Bigraphs

Bigraphs are an emerging modeling formalism for structures in ubiquitous computing. Besides an algebraic notation, which can be adopted to provide an algebraic syntax for bigraphs, the bigraphical theory introduces a visual concrete syntax which is intuitive and unambiguous at the same time; the standard visual notation can be customized and thus tailored to domain-specific requirements. However, in contrast to modeling standards based on the Meta-Object Facility (MOF) and domain-specific languages typically used in model-driven engineering (MDE), the bigraphical theory lacks a precise definition of an abstract syntax for bigraphical modeling languages. As a consequence, available modeling and analysis tools use proprietary formats for representing bigraphs internally and persistently, which hampers the exchange of models across tool boundaries. Moreover, tools can be hardly integrated with standard MDE technologies in order to build sophisticated tool chains and modeling environments, as required for systematic engineering of large systems or fostering experimental work to evaluate the bigraphical theory in real-world applications. To overcome this situation, we propose an abstract syntax for bigraphs which is compliant to the Essential MOF (EMOF) standard defined by the Object Management Group (OMG). We use typed graphs as a formal underpinning of EMOF-based models and present a canonical mapping which maps bigraphs to typed graphs in a natural way. We also discuss application-specific variation points in the graph-based representation of bigraphs. Following standard techniques from software product line engineering, we present a framework to customize the graph-based representation to support a variety of application scenarios.

VMTL: a language for end-user model transformation

Model transformation is a key enabling technology of Model-Driven Engineering (MDE). Existing model transformation languages are shaped by and for MDE practitioners--a user group with needs and capabilities which are not necessarily characteristic of modelers in general. Consequently, these languages are largely ill-equipped for adoption by end-user modelers in areas such as requirements engineering, business process management, or enterprise architecture. We aim to introduce a model transformation language addressing the skills and requirements of end-user modelers. With this contribution, we hope to broaden the application scope of model transformation and MDE technology in general. We discuss the profile of end-user modelers and propose a set of design guidelines for model transformation languages addressing them. We then introduce Visual Model Transformation Language (VMTL) following these guidelines. VMTL draws on our previous work on the usability-oriented Visual Model Query Language. We implement VMTL using the Henshin model transformation engine, and empirically investigate its learnability via two user experiments and a think-aloud protocol analysis. Our experiments, although conducted on computer science students exhibiting only some of the characteristics of end-user modelers, show that VMTL compares favorably in terms of learnability with two state-of the-art model transformation languages: Epsilon and Henshin. Our think-aloud protocol analysis confirms many of the design decisions adopted for VMTL, while also indicating possible improvements.

MDE Approach for the Establishment of a Service Level Agreements Monitoring by Trusted Third Party in the Cloud Computing

Establishing and monitoring SLA violations in real-time has become a critical issue for Cloud Computing. In this paper the authors investigate this issue and propose a model to express the SLA contract requirements using Model Driven Engineering (MDE), as a mean for establishing service level agreements between a cloud provider and cloud customer in the context of a particular service provision. The participation of a Trusted Third Party (TTP) may be necessary in order to resolve conflicts between prospective signatories, likewise to monitor SLA violations in real-time in the goal to ensure online monitoring cloud services and provide better than best-effort behavior for clouds. The main focus of this work is firstly to use MDE technology for the creation of the SLA contract and then to integrate TTP that should be able to apply an advanced penalty model that guarantees the performance and the reliability of the Cloud.

Systems analysis of life cycle of large-scale information-control systems

Results of analysis of problems associated with life cycle cost reduction for large-scale information-control systems are presented. Rational design concepts with application of an aspect-oriented method for large-scale systems are described. An approach to life cycle organization corresponding to the ISO/IEC 12207-2008 standard on the basis of domain engineering and model-driven engineering technologies is proposed. The paper shows a necessity of using the approach within a unified mathematical semantic base supplied by category theory. The approach has been tested during development of application information-control systems in energy production.

Applicability of real-time schedulability analysis on a software radio protocol

In this paper, we present our experience on integrating timing constraint verification and analysis, by using the real-time scheduling theory, in an industrial context. The verification process has been integrated into a design flow at THALES Communications & Security. We focus our work on Software Radio Protocols (SRP). We have used Model-Driven Engineering technologies and the Cheddar schedulability analysis tool for our experiment. We show how we have modeled a complete SRP in UML MARTE, a profile for real-time embedded systems, before using model transformation to extract information for schedulability analysis with Cheddar.

Specification of data schema mappings using weaving models

Weaving models are used in the model driven engineering (MDE) community for various application scenarios related to model mappings. However, an analysis of its suitability for specification of heterogeneous schema mappings reveals that weaving models lack support for mapping rules and, therefore, cannot prevent mapping specifications which are semantically meaningless, wrong or disallowed. This paper proposes a solution which overcomes the identified open issue by providing the explicit support for semantic mapping rules. It is based on introduction of weaving metamodels augmented with constraints written in OCL. The role of OCL constraints is to restrict mapping specifications to only those which are semantically meaningful. Using well known MDE technologies, such as EMF and QVT, an existing tool is used to validate the presented solution. This solution is also successfully evaluated in practice.

An approach for the semantic interoperability of ISO EN 13606 and OpenEHR archetypes

The communication between health information systems of hospitals and primary care organizations is currently an important challenge to improve the quality of clinical practice and patient safety. However, clinical information is usually distributed among several independent systems that may be syntactically or semantically incompatible. This fact prevents healthcare professionals from accessing clinical information of patients in an understandable and normalized way. In this work, we address the semantic interoperability of two EHR standards: OpenEHR and ISO EN 13606. Both standards follow the dual model approach which distinguishes information and knowledge, this being represented through archetypes. The solution presented here is capable of transforming OpenEHR archetypes into ISO EN 13606 and vice versa by combining Semantic Web and Model-driven Engineering technologies. The resulting software implementation has been tested using publicly available collections of archetypes for both standards.

A model-driven approach for representing clinical archetypes for Semantic Web environments

The life-long clinical information of any person supported by electronic means configures his Electronic Health Record (EHR). This information is usually distributed among several independent and heterogeneous systems that may be syntactically or semantically incompatible. There are currently different standards for representing and exchanging EHR information among different systems. In advanced EHR approaches, clinical information is represented by means of archetypes. Most of these approaches use the Archetype Definition Language (ADL) to specify archetypes. However, ADL has some drawbacks when attempting to perform semantic activities in Semantic Web environments. In this work, Semantic Web technologies are used to specify clinical archetypes for advanced EHR architectures. The advantages of using the Ontology Web Language (OWL) instead of ADL are described and discussed in this work. Moreover, a solution combining Semantic Web and Model-driven Engineering technologies is proposed to transform ADL into OWL for the CEN EN13606 EHR architecture.

Guest Editor's Introduction: Model-Driven Engineering

Model-driven engineering technologies offer a promising approach to address the inability of third-generation languages to alleviate the complexity of platforms and express domain concepts effectively.