Allaoua Chaoui

Formal Study of Reconfigurable Manufacturing Systems: A High Level Petri Nets Based Approach

A Reconfigurable Manufacturing System RMS has the ability to adapt itself for new requirements and to handle accidental damages. This reconfiguration makes the system more efficient, thus, enhances its productivity. However, the development process of these systems and their reliability remain a big challenge. Formal methods are considered as one issue for designing theses systems and analysing their properties. The objective of this paper is to apply Petri Nets based methods in the modelling and simulation of RMS. In particular, RONs Reconfigurable Object Nets are used as a high level Petri Nets to catch the reconfigurability aspect in RMSs. This exploitation allows the developer to simulate, and verify formally the correctness and reliability of the RMSs.

Modeling and Analysis of Reconfigurable Systems Using Flexible Petri Nets

Using Petri nets to model reconfigurable systems, where structure changes during runtime, have been one of the research axes in high level Petri nets domain. Numerous formalisms with different particularities have been proposed. These formalisms try to deal with some aspects of these systems. In the present paper, we propose a new PNets-based formalism “Flexible Nets” that we consider more general and more adequate to model reconfigurable systems. The current formalism allows to the net to be flexible and its structure can be changed with few constraints. Places, transitions, and arcs can be added and deleted from the net during its execution. These qualities will offer to the developer a sophisticated tool to model easily his system. We present the formal definition of the formalism, a case study on a real and complex system, and then we will discuss some analysis and verification issues.

Modeling and Analysis of Reconfigurable Systems Using Flexible Nets

Reconfigurable systems, with dynamic structure at runtime, know a large usage in mobile code systems and mobile networks. Developing these systems and ensuring there correction can require the exploitation of formal tools. Petri Nets were well used in modeling and verification of these systems. High Level Petri Nets were proposed to model some aspects of these systems. In this paper, we propose a new formalism “Flexible Nets” with a high level dynamicity. This formalism will allow an easy and intuitive modeling of reconfigurable systems. The expressive power of the current formalism is due to the feature that all constituents of the net’s structure can be added or deleted during the execution of the net. This paper presents the formal definition of the formalism, gives an example on mobile code systems, and discusses some analysis issues of the current formalism.

Modeling and Verification of RBAC Security Policies Using Colored Petri Nets and CPN-Tool

Role Based Access Control (RBAC) is more and more applied to de- sign and implement security policies in large networking systems. Although the elegance of this model, the design process of a security policy remains a chal- lenge. The consistence and the correctness of the policy are crucial. Formal verification is one of the techniques, which can be used to prove that the designed policy is consistent. In this paper 1 , we present a concrete formal mod- eling/analysis approach for RBAC policies. The modeling phase uses Colored Petri Nets (CPN) and the generated models will be analyzed using the CPN-tool. This analysis will wallow to prove many important proprieties about the RBAC security policy.

Using High Level Petri Nets in the Modelling, Simulation and Verification of Reconfigurable Manufacturing Systems

In Reconfigurable Manufacturing Systems (RMSs), the structure of the system can be changed during execution of the system. This reconfiguration can be motivated by a new requirement in the production process, or to avoid some problems caused by machines breakdowns. These systems offer a high flexibility leading to more productivity and efficiency. However, their design is more complicated implying new techniques and paradigms. The use of formal high level Petri Nets offers the ability to design these systems and to analyse or prove their properties. In this paper, we apply Reconfigurable Object Nets (RONs) for the modelling, simulation and analysis of reconfigurable manufacturing systems. We propose a formal approach, where the reconfiguration is specified as graph transformations, the simulation is realized using the RON-tool, and the analysis exploits some software tools such as TINA-tool and PIPE-tool.

Towards mobility for Caml Light

In this paper, we discuss the design of an experimental language, mCamllight which extends the functional programming language Caml Light to support concurrent and distributed programming. It is also aimed towards mobility. In contrast to others solutions, we chose to have an asynchronous system like in ERLANG, where sending and receiving do not to have to occur simultaneously, and mCamllight is tailored for distributed memory systems. It offers a few primitives with very simple semantics.

Design of A Concurrent Caml Light: ACCL

In this paper we propose an extension of the functional programming language Caml Light called ACCL for A Concurrent Caml Light which aims to encompass functional, imperative and concurrent programming paradigms in a single programming language. For the concurrent extension of Caml Light, we offer a few primitives with very simple semantics by using the model of ERLANG functional programming language. Support for dynamic process creation and inter process asynchronous communication are the two of the essential extensions to Caml Light language. This proposed language will be developed further to support distributing programming and mobile computation paradigms.