Towards a Unified Notation to Represent Model Transformation

In order to unify our internal exchange and communication about transformations, we propose TrML (Transformation Modeling Language), a unified UML notation to design model transformations. This proposal aims to reify the synthesis of existing notations dedicated to transformation modeling. TrML is independent from implementation details and could be adapted to several transformation engines. To let TrML run on top of existing engine, we transform TrML model to a model accepted by the engine. But, which language should we use for the first transformation? TrML, the targeted engine or another one? In this article we will describe how we bootstrap our new language on top of existing transformation engines

A BPMN-Based Design and Maintenance Framework for ETL Processes

Business Intelligence (BI) applications require the design, implementation, and maintenance of processes that extract, transform, and load suitable data for analysis. The development of these processes (known as ETL) is an inherently complex problem that is typically costly and time consuming. In a previous work, we have proposed a vendor-independent language for reducing the design complexity due to disparate ETL languages tailored to specific design tools with steep learning curves. Nevertheless, the designer still faces two major issues during the development of ETL processes: (i) how to implement the designed processes in an executable language, and (ii) how to maintain the implementation when the organization data infrastructure evolves. In this paper, we propose a model-driven framework that provides automatic code generation capability and ameliorate maintenance support of our ETL language. We present a set of model-to-text transformations able to produce code for different ETL commercial tools as well as model-to-model transformations that automatically update the ETL models with the aim of supporting the maintenance of the generated code according to data source evolution. A demonstration using an example is conducted as an initial validation to show that the framework covering modeling, code generation and maintenance could be used in practice

A Collaborative testbed Web Tool for Learning Model Transformation in Software Engineering Education

Software Engineering provides mechanisms to design, develop, manage and maintain social and collaborative software systems. At present, the Software Engineering Curricula includes teaching Model-Driven Engineering (MDE) as a new paradigm that enables higher productivity, attempting to maximize compatibility between systems. Modern learning methods MDE require the use of practical approaches to analyze new model-transformation techniques. Model transformations are carried out by using very high-level languages, like the ATL language. This model transformation language is built as a plugin for the Eclipse framework, and users who want to collaborate and develop software with it, have some difficulties executing ATL transformations outside this platform. To handle models at runtime, it is interesting to perform the transformations in a standalone way. In this context, we have developed a testbed web tool which aims to be useful for learning model transformation techniques. The tool offers a Graphical User Interface to test and verify the involved model transformations.The proposal is useful as a collaborative scenario for learning MDE and model transformation issues and techniques in Software Engineering education

Model Transformation Modularization as a Many-Objective Optimization Problem

Model transformation programs are iteratively refined, restructured, and evolved due to many reasons such as fixing bugs and adapting existing transformation rules to new metamodels version. Thus, modular design is a desirable property for model transformations as it can significantly improve their evolution, comprehensibility, maintainability, reusability, and thus, their overall quality. Although language support for modularization of model transformations is emerging, model transformations are created as monolithic artifacts containing a huge number of rules. To the best of our knowledge, the problem of automatically modularizing model transformation programs was not addressed before in the current literature. These programs written in transformation languages, such as ATL, are implemented as one main module including a huge number of rules. To tackle this problem and improve the quality and maintainability of model transformation programs, we propose an automated search-based approach to modularize model transformations based on higher-order transformations. Their application and execution is guided by our search framework which combines an in-place transformation engine and a search-based algorithm framework. We demonstrate the feasibility of our approach by using ATL as concrete transformation language and NSGA-III as search algorithm to find a trade-off between different well-known conflicting design metrics for the fitness functions to evaluate the generated modularized solutions. To validate our approach, we apply it to a comprehensive dataset of model transformations. As the study shows, ATL transformations can be modularized automatically, efficiently, and effectively by our approach. We found that, on average, the majority of recommended modules, for all the ATL programs, by NSGA-III are considered correct with more than 84% of precision and 86% of recall when compared to manual solutions provided by active developers. The statistical analysis of our experiments over several runs shows that NSGA-III performed significantly better than multi-objective algorithms and random search. We were not able to compare with existing model transformations modularization approaches since our study is the first to address this problem. The software developers considered in our experiments confirm the relevance of the recommended modularization solutions for several maintenance activities based on different scenarios and interviews.Comisión Interministerial de Ciencia y Tecnología TIN2015-70560-RJunta de Andalucía P12-TIC-186

Pattern-based model transformation: a metamodel-based approach to model evolution

Software systems continue to grow in complexity at a rapid pace, creating systems that are complex to build and evolve. The problems that accompany changes in requirements, system upgrades, and error correction produce a desire for software evolution methods that increase the efficiency and effectiveness of adapting complex software to changes. As software systems evolve, design models must be modified to accommodate the required changes. Techniques that control the changes to models in a systematic manner are a key to model evolution. A process that improves the ability to effectively modify a design, thereby enhancing design qualities, supports the need for improved model evolution techniques. Design patterns are common forms of reusable design experiences. They offer solutions to common design problems, reduce complexity by naming and defining abstractions, and provide a foundation for building reusable software. Well-known pattern solutions are expressed in a natural language as fragments of code which are sometimes difficult to understand and implement by software modelers. With increased focus on development of model-driven approaches, rigorous descriptions of design patterns that capture solutions during design instead of implementation are needed. This research defines an approach for the transformation of models that supports controlled model evolution. More precisely, a process for capturing design patterns in UML class diagrams is defined. This process involves defining a metamodel-level representation which specifies how a software developer can introduce design patterns into existing design models. We defined transformation patterns as an extension of the UML metamodel to characterize source and target model elements. The transformation pattern consists of specialized metamodel elements that specify the structure of source and target metamodels. Transformation patterns were specified for the Abstract Factory, Bridge and Visitor design patterns to show how the model-level transformations can be perform on patterns that represent different functionalities. We developed an action language to specify constructs which add, delete, retrieve and connect model elements. We used the constructs of the action language to define transformation specifications that implement model-level transformations on class diagrams. To determine the potential of this approach we manually implemented the transformation specification on a UML design

A Fast and Accurate Cost Model for FPGA Design Space Exploration in HPC Applications

Heterogeneous High-Performance Computing (HPC) platforms present a significant programming challenge, especially because the key users of HPC resources are scientists, not parallel programmers. We contend that compiler technology has to evolve to automatically create the best program variant by transforming a given original program. We have developed a novel methodology based on type transformations for generating correct-by-construction design variants, and an associated light-weight cost model for evaluating these variants for implementation on FPGAs. In this paper we present a key enabler of our approach, the cost model. We discuss how we are able to quickly derive accurate estimates of performance and resource-utilization from the design’s representation in our intermediate language. We show results confirming the accuracy of our cost model by testing it on three different scientific kernels. We conclude with a case-study that compares a solution generated by our framework with one from a conventional high-level synthesis tool, showing better performance and power-efficiency using our cost model based approach

Integrating Refinement into Software Development Tools

AbstractIt is a challenge for automatic tool support to formal design by refinement transformations. In this paper, we bring this matter to the attention of the research community and discuss a component-based model transformational approach for integrating refinement into software development tools. Models, their consistency and correctness, in an object-oriented and component-based development process are defined in rCOS, that is a refinement calculus recently developed at UNU-IIST. Correctness preserving transformations between models are formalized and proved as refinement rules in rCOS. In this paper, we will discuss on how these transformations can be implemented in the relations language of Query/View/Transformation (QVT) standardized by OMG

Symbolic Model-Checking using ITS-tools

International audienceWe present the symbolic model-checking toolset ITS-tools. The model-checking back-end engine is based on hierarchical set decision diagrams (SDD) and supports reachability, CTL and LTL model-checking, using both classical and original algorithms. As front-end input language, we promote a Guarded Action Language (GAL), a simple yet expressive language for concurrency. Transformations from popular formalisms into GAL are provided enabling fully symbolic model-checking of third party (Uppaal, Spin, Divine...) specifications. The tool design allows to easily build your own transformation, leveraging tools from the meta-modeling community. The ITS-tools additionally come with a user friendly GUI embedded in Eclipse

Analysing tactics in architectural patterns

We present an approach to analyse the application of tactics in architectural patterns. We define and illustrate the approach by resorting to Archery, a language for specifying, analysing and verifying architectural patterns. The approach consists of characterising the design principles of an architectural pattern as constraints, expressed in the language, and then, establishing a refinement relation based on their satisfaction. The application of tactics preserving refinement preserves the original design principles expressed themselves as constraints for the architectural pattern. The paper’s focus on fault-tolerance tactics, and identifies a set of requirements for a semantic framework characterising them. Model transformations to represent their application are discussed and illustrated through two case studies.FC

From napkin sketches to reliable software

In the past few years, model-driven software engineering (MDSE) and domain-specific modeling languages (DSMLs) have received a lot of attention from both research and industry. The main goal of MDSE is generating software from models that describe systems on a high level of abstraction. DSMLs are languages specifically designed to create such models. High-level models are refined into models on lower levels of abstraction by means of model transformations. The ability to model systems on a high level of abstraction using graphical diagrams partially explains the popularity of the informal modeling language UML. However, even designing simple software systems using such graphical diagrams can lead to large models that are cumbersome to create. To deal with this problem, we investigated the integration of textual languages into large, existing modeling languages by comparing two approaches and designed a DSML with a concrete syntax consisting of both graphical and textual elements. The DSML, called the Simple Language of Communicating Objects (SLCO), is aimed at modeling the structure and behavior of concurrent, communicating objects and is used as a case study throughout this thesis. During the design of this language, we also designed and implemented a number of transformations to various other modeling languages, leading to an iterative evolution of the DSML, which was influenced by the problem domain, the target platforms, model quality, and model transformation quality. Traditionally, the state-space explosion problem in model checking is handled by applying abstractions and simplifications to the model that needs to be verified. As an alternative, we demonstrate a model-driven engineering approach that works the other way around using SLCO. Instead of making a concrete model more abstract, we refine abstract models by transformation to make them more concrete, aiming at the verification of models that are as close to the implementation as possible. The results show that it is possible to validate more concrete models when fine-grained transformations are applied instead of coarse-grained transformations. Semantics are a crucial part of the definition of a language, and to verify the correctness of model transformations, the semantics of both the input and the output language must be formalized. For these reasons, we implemented an executable prototype of the semantics of SLCO that can be used to transform SLCO models to labeled transition systems (LTSs), allowing us to apply existing tools for visualization and verification of LTSs to SLCO models. For given input models, we can use the prototype in combination with these tools to show, for each transformation that refines SLCO models, that the input and output models exhibit the same observable behavior. This, however, does not prove the correctness of these transformations in general. To prove this, we first formalized the semantics of SLCO in the form of structural operational semantics (SOS), based on the aforementioned prototype. Then, equivalence relations between LTSs were defined based on each transformation, and finally, these relations were shown to be either strong bisimulations or branching bisimulations. In addition to this approach, we studied property preservation of model transformations without restricting ourselves to a fixed set of transformations. Our technique takes a property and a transformation, and checks whether the transformation preserves the property. If a property holds for the initial model, which is often small and easy to analyze, and the property is preserved, then the refined model does not need to be analyzed too. Combining the MDSE techniques discussed in this thesis enables generating reliable and correct software by means of refining model transformations from concise, formal models specified on a high level of abstraction using DSMLs