Franklin Ramalho

Ecore representation for extending PNML for Input-Output Place-Transition nets

This paper presents a metamodel for the Input-Output Place-Transition nets (IOPT nets), a Petri net class targeted at controllers modeling. The proposed metamodel reuses many of the elements of the Petri Net Markup Language (PNML) metamodel, such as places, transitions, and arcs; it extends the PNML metamodel for Place/Transition nets to comprise concepts inherent to IOPT nets. The IOPT nets metamodel is described in Ecore format, putting IOPT nets in the puzzle of MDA artifacts taking benefit from the MDA infrastructure.

Metamodel reuse with MOF

As model-driven development promotes metamodels as key assets it raises the issue of their reuse throughout a model-driven product line life cycle. One recurrent reuse need occurs when metamodeling integrated multi-language platforms: one construct from one language is integrated to constructs from other languages by generalizing it, making it more expressive. None of the metamodel assembly facilities provided by MOF and UML (import, merge and combine) or others proposed in previous work adequately addresses this need. We thus propose a new reuse and generalize facility for such purpose.

An Extended MDA Architecture for Ensuring Semantics-Preserving Transformations

MDA is a current trend that shifts the focus and effort from implementation during the development process to models, metamodels and transformations. The four-layer MDA architecture still suffers from the lack of formalization of its artifacts and processes leading to ambiguity and low reliability problems. For instance, currently there is no way for ensuring that MDA transformations are semantic-preserving. In this paper we tackle this problem by incorporating well-consolidated formal methods approaches in the MDA architecture. We propose extending the M1 and M2 layers of the MDA architecture towards the definition of static and dynamic semantic models, both crucial to extract the semantics of any model. The extension includes: (i) a semantic metamodel and a set of transformations representing semantic equations; and (ii) a set of evaluation reduction rules for semantic models in order to extract the meaning from their states and automatic proofs of conformance between these models. In order to validate this work, a proof of concept has been implemented and evaluated verifying conformance between models that represent imperative constructs of programming languages in the modelware context.

UML-based design test generation

In this paper we investigate and propose a fully automated technique to perform conformance checking of Java implementations against UML class diagrams. In our approach, we reused the DesignWizard Java API that allows us to write design rules as JUnit tests, i.e., to write them as code directly in the programming language. We fully pursued MDA as the approach for generating the design tests and hence we used several MDA artifacts, such as metamodels, models and transformations. A proof of concept of the technique has been implemented and evaluated. We performed several experiments on simple scenarios. Simple designs involving classes, associations, inheritance have been checked. Compared to previous related work, the advantage of our approach lies in the fact that we automatically generate design tests from UML class diagrams to Java code that play the dual role of design test and implementation language. Thus, we check the conformance between the design and the implementation.

Automatic generation of built-in contract test drivers

Automatic generation of platform-independent and -dependent built-in contract test drivers that check pairwise interactions between client and server components is presented, focusing on the built-in contract testing (BIT) method and the model-driven testing approach. Components are specified by UML diagrams that define the contract between client and server, independent of a specific platform. MDA approaches are applied to formalize and perform automatic transformations from a platform-independent model to a platform-independent test architecture according to a BIT profile. The test architecture is mapped to Java platform models and then to test code. All these transformations are specified by a set of transformation rules written in the Atlas Transformation Language (ATL) that are automatically performed by the ATL engine. The solution named the MoBIT tool is applied to case studies in order to investigate the expected benefits and challenges to be faced.

Properties Preservation in Distributed Execution of Petri Nets Models

Model-based development for embedded system design has been used to support the increase of system’s complexity. Several modeling formalisms are well matched for usage within this area. One of the goals of this work is to contribute to the usage of Petri nets as system specification language within model-based development of embedded systems having MDA proposals as a reference for the development flow. Distributed execution of the Petri net model is achieved through model partitioning into sub-modules. System decomposition is obtained through net splitting operation. Two types of implementation platforms were considered: compliant and non-compliant with zero time delay for communication between modules. Using model-checking techniques, properties associated with the execution of the distributed models in both types of platforms were compared with the execution of the initial (centralized) Petri net model.

SysVeritas: A Framework for Verifying IOPT Nets and Execution Semantics within Embedded Systems Design

We present a rewriting logic based technique for defining the formal executable semantics of a non-autonomous Petri net class, named Input-Output Place/Transition nets (IOPT nets), designed for model-based embedded system’s development, according to the MDA initiative. For this purpose, we provide model-to-model transformations from ecore IOPT models to a rewriting logic specification in Maude. The transformations are defined as semantic mappings based on the respective metamodels: the IOPT metamodel and the Maude metamodel. Also, we define model to-text transformations for the generation of the model execution code in the rewriting logic framework. Hence, we present a translational semantics composed by two components: (i) the denotational one, considering as semantic domains the operations, equations, and properties that specify the Petri net structure, signals, and events according to the commutative monoid view; and (ii) the operational one, that changes the interleaving semantics of Maude using rewriting rules specified at the Maude metalevel to provide a maximal step semantics for transitions with arcs, test arcs, and priorities. Additionally, this work gives architectural advices in order to compose new semantics specifications by simple component substitution. Due to its simulation and verification capabilities for control systems, the presented work was applied to a domotic project that intends to save energy in residential buildings.

Petri Net Based Specification and Verification of Globally-Asynchronous-Locally-Synchronous System

This paper shows a methodology for Globally-Asynchronous-Locally-Synchronous (GALS) systems specification and verification. The distributed system is specified by non-autonomous Petri net modules, obtained after the partition of a (global) Petri net model. These modules are represented using IOPT (Input-Output Place-Transition) Petri net models, communicating through dedicated communication channels forming the GALS system under analysis. This set of modules is then automatically translated into Maude code through a MDA approach. As the modules of GALS systems run concurrently, the Maude semantics for concurrent objects is used along with message representation. Finally, as a particular case, the system state space is generated from the Maude specification of the GALS system, allowing property verification.

Towards a requirements traceability process centered on the traceability model

Requirements traceability (RT) has been acknowledged as a valuable activity in the software development process. Its importance is reflected in different quality standards, which dictates that requirements should be traceable through the software development life-cycle. However, there is not a consensus about the traceability process and, as a consequence, RT practices cannot be unified across different organizational settings. Identifying common aspects to the RT process has been recognized as one of the grand challenges of RT. Even though, researches regarding improvements in requirements engineering (RE) neglect the traceability research scope. Therefore, is this paper, we propose and detail a RT process, specifying its workflow, actors, responsibilities and inputs/outputs as well as establishing contracts that govern the proposed process phases. To evaluate the proposed process, we have conducted an empirical experiment in a real project under development for the federal police of Brazil. We observed time, precision, recall and efficiency metrics and concluded that the proposed process improves the performance of RT practices. As a final remark, the proposed process contributes towards the discussion of common aspects of the RT process.

Metrics to Measure the Change Impact in ATL Model Transformations

The Model-Driven Development (MDD) shifts the focus on code to models in the software development process. In MDD, model transformations are elements that play important role. In the software process, MDD projects evolve as changes in their transformations are frequent. Before applying changes it is important to measure their impacts in the transformation. However, currently no technique helps practitioners in this direction. In this work, we conducted an exploratory study to identify the criteria used by practitioners to measure the impact of changes in model transformations. As a result, we propose a set of metrics to measure such impacts. By measuring the change impact, practitioners can (i) save effort and development time for estimating costs to apply changes; and (ii) better schedule and prioritize changes according to the impact.