Farid Mokhati

Applying Model Checking to Concurrent UML Models

We present, in this paper, a framework supporting a formal verification of concurrent UML models using the Maude language. We consider both static and dynamic features of concurrent object-oriented systems. We focus on UML class, state and communication diagrams. The formal and object-oriented language Maude, based on rewriting logic, supports formal specification and programming of concurrent systems, as well as model checking. The major motivations of this work are: (1) translating concurrent UML diagrams into a Maude formal specification and (2) applying model checking to the generated specifications. The approach is illustrated using a concrete case study.

Verifying UML Diagrams with Model Checking: A Rewriting Logic Based Approach

We present, in this paper, a framework supporting a formal verification of UML diagrams using the Maude language. The approach considers both static and dynamic features of object-oriented systems. We focus, in particular, on UML class, state and communication diagrams. The formal and object-oriented language Maude, based on rewriting logic, supports formal specification and programming of concurrent systems, as well as model checking. The major motivations of this work are: (1) bind together the UML notation and the Maude language (2) preserve the coherence in object-oriented systems description, (3) use model checking techniques to support formally their verification process. The generated Maude specifications, from the considered UML diagrams, are validated by simulation and model checking. The approach is illustrated using a concrete case study.

Generating Maude Specifications From UML Use Case Diagrams

This paper presents a systematic approach supporting the translation of UML use case diagrams, describing the functional requirements of a system, into a Maude formal specification. The proposed approach also considers the static and dynamic features of object-oriented systems. The formal and object-oriented language Maude, based on rewriting logic, supports formal specification and programming of concurrent systems. The major motivations of this work are: (1) translating the functional requirements of an object-oriented system, specified using UML use case diagrams, into a Maude specification, (2) translating its static and dynamic aspects, described using UML class, communication and state-transitions diagrams respectively, into a Maude specification, and (3) integrating the formal verification of the consistency of the models, since the analysis phase. A case study is presented to illustrate our approach.

A Tool for Specifying and Validating Agents' Interaction Protocols: From Agent UML to Maude

To achieve the multi-agent systems’ goals, agents interact to exchange information, to cooperate and to coordinate their tasks. Interaction is generally recognized as an important characteristic of multi-agent systems (MAS). The usual approaches to model agents’ interactions consist of describing them as protocols [Hug04]. In the literature, several representation formalisms of agents’ interactions have been proposed. AUML is one among the most used formalisms [Hug02]. However, AUML diagrams only offer a semi-formal specification of interactions. Indeed, the lack of formal semantics in AUML, can lead to several incoherencies in the description of a MAS’ behaviour. We present, in this paper, a visual tool that essentially allows: (1) translating the description of agents’ interaction protocols (AIP), specified by means of AUML formalism, in a Maude specification and, (2) validating the generated formal descriptions through simulation. Based on rewriting logic, the formal and object-oriented language Maude offers an interesting way for concurrent systems formal specification and programming. By an example of multi-agent systems interaction protocol, we illustrate the proposed translation and the developed tool.

Toward a new aspect-mining approach for multi-agent systems

A semi-automatic hybrid aspect mining approach for agent-oriented code is proposed.The approach is based on both static and dynamic analyzes.Identifying cross-cutting concerns in existing multi-agent systems code is the main motivation.The proposed approach is supported by a software tool called MAMIT. Many aspect mining techniques have been proposed for object-oriented systems. Unfortunately, aspect mining for multi-agent systems is an unexplored research area. The inherent specificities of multi-agent systems (such as autonomy, pro-activity, reactivity, and adaptability) make it difficult to understand, reuse and maintain their code. We propose, in this paper, a (semi-automatic) hybrid aspect mining approach for agent-oriented code. The technique is based on both static and dynamic analyzes. The main motivations of this work are (1) identifying cross-cutting concerns in existing agent-oriented code, and (2) making them explicitly available to software engineers involved in the evolution of agent-oriented code in order to facilitate its refactoring and, consequently, to improve its understandability, reusability and maintainability. The proposed approach is supported by a software tool, called MAMIT (MAS Aspect-MIning Tool), that we developed. The approach and the associated tool are illustrated using a concrete case study.

Complexity Measurement of Multi-Agent Systems

Multi-Agent Systems (MAS) is a promising software paradigm. Considered as a natural metaphor to modeling complex systems, MAS are applied to develop a wide range of applications. However, the developed systems complexity is a hard obstacle to understand and maintain them. In this paper, some metrics are presented to measure the complexity of MAS. The proposition of these metrics is passed through the proposition of a complexity model for MAS. To validate our proposal, a tool has been developed to measure the JADE-based applications complexity. Furthermore, the collected metrics can also be used as a base to estimate the required effort to maintain JADE-based applications.

SUPPORTING FORMAL VERIFICATION OF DIMA MULTI-AGENTS MODELS: TOWARDS A FRAMEWORK BASED ON MAUDE MODEL CHECKING

Model Checking based verification techniques represent an important issue in the field of concurrent systems quality assurance. The lack of formal semantics in the existing formalisms describing multi-agents models combined with multi-agents systems complexity are sources of several problems during their development process. The Maude language, based on rewriting logic, offers a rich notation supporting formal specification and implementation of concurrent systems. In addition to its modeling capacity, the Maude environment integrates a Model Checker based on Linear Temporal Logic (LTL) for distributed systems verification. In this paper, we present a formal and generic framework (DIMA-Maude) supporting formal description and verification of DIMA multi-agents models.

Testing HMAS-based applications

Organization-Based Multi-Agent Systems are receiving increasingly more attention in the field of complex and distributed systems development. Holonic Multi-Agent Systems (HMAS) are considered as well known organization allowing the construction of complex systems that are efficient in terms of use of resources, highly resilient to disturbances and adaptable to changes in their environment. However, HMAS-based applications development is not mature enough yet. Particularly, testing activities, which represent an important task in their quality assurance, are not well covered. This paper aims at proposing a new model-based testing technique for holonic agents. The technique uses genetic algorithms and takes into account the evolution (successive versions) of an agent. The approach is organized in two main phases that are conducted iteratively. The first phase focuses on the detection of a new version of an agent under test. The second phase addresses the testing of each new detected version. The new version of the agent is analyzed in order to generate a behavioral model on which is based the generation of test cases. The test cases generation process focuses on the new (and/or changed) parts of the agent behavior. In this way, the technique supports an incremental update of the test cases, which is a crucial issue. A software tool that we developed supports the proposed technique. The approach and associated tool are illustrated using a concrete case study.

A Novel Organizational Model for Real Time MAS: Towards a Formal Specification

In this paper we present our approach allowing the translation of Real Time Multi-Agents Systems (RT-MAS) organizational requirements described by extended AUML (Agent UML Language) diagrams into a formal specification written in Real Time Maude language (RT-Maude). In fact, the approach is an extension of our previous work [1] that consists in extending AUML diagrams (Temporal AUML organization use case diagram and Temporal AUML organization class diagram) by using stereotypes notions and meta-model organizations entities for taking into account RT-MAS specificities. Once elaborated, these different diagrams undergo a validation to assure inter-and intra model coherence. The formal and object oriented language RT-Maude, base on rewriting logic, supports formal specification and programming of concurrent systems. The main motivations of this work are: (1) formalizing the organizational requirements of RT-MAS by using RT-Maude language, and (2) integrating the validation of the coherence models, since the analysis phase.

Specifying DIMA multi-agents models using maude

The lack of formalism and rigor in existing multi-agents models often leads to ambiguities and different interpretations. Those weaknesses combined with the inherent complexity of multi-agents systems generate many problems in their development process. Using formal notations to specify multi-agents systems’ behavior makes it possible to produce precise description. This also offers a better support to their verification and validation process. The Maude language, based on rewriting logic, presents a rich notation supporting formal specification and implementation of concurrent systems. In this paper, we demonstrate the feasibility and the interest of formalizing the behavior of DIMA model’s agents with the Maude language. The elaborated formal approach captures the inherent aspects of a DIMA model. The generated Maude descriptions have been validated using the platform supporting this language. Moreover, the proposed approach is generic and extensible. It offers, in particular, the advantage of being applicable to all multi-agents systems based on DIMA architecture and presents interesting extension possibilities.