Blockchain technologies have emerged to serve as a trust basis for the monitoring and execution of business processes, particularly business process choreographies. However, dealing with changes in smart contract-enabled business processes remains an open issue. For any required modification to an existing smart contract (SC), a new version of the SC with a new address is deployed on the blockchain and stored in a contract registry. Moreover, in a choreography, a change in a partner process might affect the processes of other partners, and thus, must be propagated to partners affected by the change. In this paper, we propose an approach overcoming the limitations of SCs and allowing for the change management of blockchain-enabled declarative business process choreographies modeled as DCR graphs. Our approach allows a partner in a running blockchain-based DCR choreography instance to change its private process. A change impacting other partners is propagated to their processes in a decentralized manner using a SC. The change propagation mechanism ensures the compatibility checks between public processes of the partners and the consistency between the private and public processes of one partner. We demonstrate the approach’s feasibility through an implemented prototype and its effectiveness via a set of evaluation tests.

Network as a Service (NaaS) enables tenants and cloud users to connect their distributed services across multiple clouds without relying on their own networking services and resources. Cloud service providers (CSPs) offer networking services as bundles delivered on a pay-per-use basis. Although service bundling is a common practice in the cloud providing multiple components as a single service, forcing the packaging of network resources in a pure bundle can severely limit visibility and control over network services. We argue that current descriptions of NaaS services lack transparency making cloud users unable to efficiently discover and consume these services from different providers. To address this issue, we propose to describe network services based on their functionality and according to the OSI model. Our approach explicitly describes bundling between network services that promotes discovery and enables users to create their own network services bundles from different CSPs.

The number of LoRaWAN networks have grown worldwide last years, offering a solution for the integration of the Internet of Things in rural and urban areas. After years of development, several performance issues and scalability limitations require to be enhanced for LoRa such as high collision rates and duty cycle limitations. Machine learning offers a chance for LoRaWAN to rise as the reference communication technology that offers the adequate communication performances for IoT. In this paper, our goal is to optimize the LoRaWAN network performances using detection mechanism and artificial intelli-gence to predict its behavior. first, we evaluate the full potential of the LoRaWAN factory setting, and we introduced a Quality of Service demanding application. Second, we constructed our proper database using available application criteria, we included a quality of service mechanism to simulate the effect of a new application connecting to a stable network and the perturbing causes. Then, we used two different methods one for classification, the second for prediction, and then the optimization. For clas-sification using Auto-Regressive and optimization it using burg algorithm and firefly algorithm, then we used the support vector machine for traffic classification, results are very promising, we were able to detect normal traffic, a normal surge, and an abnormal surge of network traffic with up to 99% accuracy. For prediction, we used a new algorithm developed by google Temporal Fusion Transformer. We were able to predict the network behaviour ahead with 14 days with 95% accuracy and up to 30 days with 80% accuracy. We were able to optimize the network to absorb the abnormal surge and return to normal in less than 60% of the normal time, uplifting the packet delivery ratio for uplink traffic by 20% and downlink traffic by 50%.

Smart Contracts (SC for short) are gaining momentum as a suitable technology for ensuring trusted execution of Business Processes (BP for short) in open environment. Nevertheless, the transactional semantics of SC which follow ACID transactions are not appropriate for BP characteristics. Indeed, it is admitted that ACID transactions are limited to cope with complex control structure and long running execution of BP. Transactional Business Processes (TBP for short) have emerged as an extension to ACID models to overcome these limits. A TBP ensures transactional reliability of advanced transactions having a control structure as complex as for BP. In this paper, we propose an approach that builds on SC and extends them to implement TBP. We extend Caterpillar, an existing BP execution engine developed on top of Ethereum, to implement our approach and support the execution of TBP.

The LoRaWAN technology is today the object of great interest in the Internet of Things context. It defines a simple network architecture offering a wide-area wireless coverage for low rate IoT applications with low power consumption for devices. The LoRaWan class A is designed for sensor networks with a focus on the uplink. LoRaWan defines an optional MAC operation, Class B, that provides the network server with the opportunities to initiate a downlink, which can be a real solution for actuators focus network. Today, Performances of Class B are not quantified and compared to default LoRaWAN class. In this paper, we propose an evaluation of Class B performance. We offer a set of realistic evaluation scenarios based on an NS-3 simulation module that we have developed for this purpose. Results show that Class B reduces the delivery delay of downlink traffic in comparison to Class A. Class B operation significantly reduces the percentage of packet loss for downlink traffic even in congested contexts. We conclude that a trade off should be made between having low access delay or packet loss. Both the NS-3 module and data are released as an open-source to the research community.

Summary This paper presents an approach for avoiding resource misallocations in Business Processes (BPs). We consider a resource misallocation as an improper combination of resources in a BP and we introduce a decision tree‐based approach to minimize these misallocations likelihoods. The approach uses a BP's event log that tracks past misallocations along with their undesirable impacts in terms of time, cost, and quality on BP instances. These impacts are identified by mining resource allocation rules, which provide a concise summary of a BP's event log and thus are also used to generate decision trees. A system demonstrating the feasibility and efficiency of the approach through experiments is presented in this paper as well.

Normative Multi-agent system (NMAS) forms a promising approach to software engineering for the development of autonomous systems, in norms-based environments. During the construction of these systems, different requirements can be considered: functional and non-functional requirement. Existing research in NMAS have mostly focused on the study of functional and behavioral requirements specification and verification, while Non-Functional Requirements (NFR) are crucial in the development of systems. They have dealt with the NFR implicitly through the capabilities of functional requirements. An important research issue refers to NFR in NMAS, i.e. how to specify and enforce NFR in NMAS that involves heterogeneous and autonomous agents. The NFR define constraints for the system and specify the qualities that a system can have, for example, security, performance, reliability, comfort, availability. Also, NFR might conflict among each other (for example, cost and quality, comfort and economy). A conflict between two NFR occurs when the fulfillment of one NFR violates another NFR. One of the main challenges currently faced in NMAS research is that of NFR specification and verification. In particular, how to specify and verify NFR in autonomous systems? In this paper, we propose a normative approach that allows the specification and verification of NFR for autonomous systems. To do this, we propose a new type of norms, called Non-Functional Norms (NFN). Indeed, our approach provides (i) a BNF normative language for specifying NFN, and (ii) a mechanism, based on Constraint Satisfaction Problem (CSP) technique, for the detection and resolution of normative conflicts. Our normative approach is also illustrated by a case study describing Smart City Management System (SCMS).

Blockchain trends cover more and more tech domains making it one of the most used technologies in the last few years. This is due to two essential aspects. First, it is a distributed peer-to-peer network where there is no need for third part to execute operations between peers. Second, blockchain implements mechanisms to make the most data sensitive operations executed in a trusted way. Regarding these attractive aspects, we intend in this work to use the blockchain technology for the implementation of touristic itineraries. We consider the latter as process choreographies involving different participants. We intend to model and execute the touristic itineraries generated from a personalized trip planner called CART in raw XML format in a way that respects this collaborative aspect and resolves the problem of trust. We will propose a pattern and its transformation rules to reconstruct the itineraries presented in declarative annotations such as XML to smart contracts written in some smart contract-specific programming language called Solidity. Experimental results show promising perspectives of the deployment of the proposed solution to execute touristic plans.

Configurable Business Process models (CBP-models for short) are inspired from the design by reuse paradigm. They present a starting point for modeling business processes. However, the individualization of these models is manual which makes it time-consuming and error-prone. Moreover, using such models, business experts are not allowed to reuse a process fragment from this model. Thus, we propose a CPB-model with a hierarchical structure and capability annotated tasks. With such a structure, it is possible to point directly to a target fragment and reuse it. Moreover, the capability-annotation enabled us to develop an algorithm that generates automatically a question flow for a given CBP-model.

Holonic Multi-Agent System (HMAS) forms a promising approach to software engineering for the modeling and development of hierarchical autonomous systems (Intelligent transportation systems, Smart city management systems, etc.). Effectively, norms concepts are well adapted to the definition of HMAS. Its can be considered as a powerful way to specify the non-functional requirements of these types of systems. Non-functional requirements can conflict with each other (for example, cost and quality, comfort and economy). One of the main challenges currently faced in HMAS research is the coherence checking of norms that specify non-functional requirements. However verification approaches are limited by the state-space of the system under study. Specifying and verifying a global normative model in a single level is then complex and difficult. However, most normative models for multi-agent systems do not take into account the complexity of coherence verification algorithms of norms. One of solutions is to employ the use of coherent refinement process of global norms. This paper proposes a Global Norms Decomposition (GND) approach for hierarchical and critical autonomous systems. Indeed, the GND approach allows (i) the specification and verification of global norms in the abstract level of the studied system, and (ii) the successive refinement of these norms using a set of refinement rules that preserve properties of the system already proven in the highest level, in order to arrive finally at a concrete normative context which constitutes the behaviour model of the system. The GND approach allows the simplification of specification of norms, for an incremental specification using a refinement process, and the reduction of complexity of checking the coherence of norms, building verification using refinement rules. Our approach is also illustrated by a case study describing smart city management system.

In current business process modelling environments, the functional perspective (also can be referred to in the literature as business capability, functionality or business function) for each process activity is limited to its label. Using labels only prevents stakeholders from easily and quickly understanding what business processes or services achieve. In this paper, we define a business capability meta-model that can be used for modelling business capabilities as entities composed of a set of actions and related properties. This meta-model is implemented as Resource Description Framework (RDF) vocabularies that help experts design their domain-specific high-level business capabilities that can be used for annotating their processes, services, applications, etc. We validate the business capability meta-model by using two evaluation methods: (1) ontological evaluation in order to make sure that there is no semantic ambiguity among its constructs; (2) interviews with domain experts to assess the ability of the model to represent real capabilities and to evaluate their point of view with respect to our approach.

With the proliferation of Cloud computing and itsincreasing adoption by research communities and IT companies,providing elastic processes has become a new research issuechallenging businesses and researchers. Ensuring processes elasticityhelps organizations to face highly variable service demandsituations or uncertain financial environments. This consist inacquiring and/or releasing resources dynamically to ensure therequired QoS and reduce expenses. Elasticity management haswitnessed a lot of attention from IT community as a pivotalissue for finding the right tradeoffs between QoS levels andoperational costs by working on developing new methods andmechanisms. However, there is a lack of solutions that supportthe evaluation of elasticity strategies used to ensure the elasticityof processes at service-level and which consider differentrequirements for different requests. In this paper, we propose aformal elasticity approach for service-based processes that allowsto evaluate and verify elasticity strategies before using them in thecloud. It is composed of an elasticity model that considers thedistinguish requirements for requests and elasticity operationsfor hybrid scaling. Additionally, we present the use of ourproposed approach to evaluate different elasticity strategies usingan Elasticity Controller. Our contribution makes it possible todefine and evaluate strategies that specify different requirementsfor different requests

Modeling and design of complex intelligent systems (Intelligent transportation systems, shared health information systems, resource sharing systems, Smart city management systems, etc.) is a very difficult task due to the lack of design processes capable of covering all the characteristics of these types of systems: systems that require both a hierarchical structure which allows to bring together different levels of abstraction within the same system and require the maintenance of regulation and social control of the various entities involved in these systems by using a set of norms. Holonic Multiagent System (HMAS) forms a promising approach to software engineering for the modeling and development of hierarchical complex systems. One of the main challenges currently faced in HMAS research is that of social control. In particular, how can the HMAS be configured and organised given their structure of control and regulation? One of the main solutions is to employ the use of norms. Therefore, norms have been proposed as a mechanism for coordinating and controlling of various entities behaviors involved in the system. In this paper, we propose a new model of norms adapted to the holonic structure of HMAS. To do this, (1) we introduce two new types of norms: internal (private) and external (public) norms; (2) we identify and verify the alignment between these two types of norms. These two types of norms have implications for the control, organization and structure of holons.

The production of huge amount of data and the emergence of cloud computing have introduced new requirements for data management. Many applications need to interact with several heterogeneous data stores depending on the type of data they have to manage: traditional data types, documents, graph data from social networks, simple key-value data, etc. Interacting with heterogeneous data models via different APIs, and multiple data store applications imposes challenging tasks to their developers. Indeed, programmers have to be familiar with different APIs. In addition, the execution of complex queries over heterogeneous data models cannot, currently, be achieved in a declarative way as it is used to be with mono-data store application, and therefore requires extra implementation efforts. Moreover, developers need to master and deal with the complex processes of cloud discovery, and application deployment and execution. In this paper we propose an integrated set of models, algorithms and tools aiming at alleviating developers task for developing, deploying and migrating multiple data stores applications in cloud environments. Our approach focuses mainly on three points. First, we provide a unifying data model used by applications developers to interact with heterogeneous relational and NoSQL data stores. Based on that, they express queries using OPEN-PaaS-DataBase API (ODBAPI), a unique REST API allowing programmers to write their applications code independently of the target data stores. Second, we propose virtual data stores, which act as a mediator and interact with integrated data stores wrapped by ODBAPI. This run-time component supports the execution of single and complex queries over heterogeneous data stores. Finally, we present a declarative approach that enables to lighten the burden of the tedious and non-standard tasks of (1) discovering relevant cloud environment and (2) deploying applications on them while letting developers to simply focus on specifying their storage and computing requirements. A prototype of the proposed solution has been developed and is currently used to implement use cases from the OpenPaaS project.

International audience

Smart environments rely on sensor data to provide necessary business intelligence in order to support decision-making. An efficient decision support model in such a context requires that sensor data are provided correctly and timely. Given the dynamicity of sensor environment, the diversity of their features and of user requirements, finding appropriate sensors having the required capabilities or replacing faulty ones constitutes a challenging task. Efficiently describing and organizing sensors in smart environments is essential to deliver a rapid adaptation to errors and availability of data. In this paper, we present an approach for organizing and indexing sensor services based on their capabilities. We introduce a feature-oriented capability model that puts forward the functional aspects of carried actions and model them as resource description framework (RDF) properties rather than focusing on the change in the state of the world. Using this model for describing sensor capabilities, we apply Formal Concept Analysis for organizing and indexing sensor services. We have experimented and evaluated our approach in the Digital Enterprise Research Institute, which has been retrofitted with various sensors to monitor temperature, motion, light and consumption of power within a building.

Recently, Sensor/Actuator Networks have become an emergent technology for various application areas such as security and surveillance applications, traffic control, logistics, energy control in public and private buildings, etc. Designing and constructing new applications using these technologies remain, however, a challenging task. Indeed, finding the relevant sensors and actuators, and combining them in a proper way in order to achieve a specific goal is not an easy task and requires several skills from different stakeholders. Moreover, sensor environments are inherently highly dynamic. Furthermore, current applications are in general tightly coupled to the underlying infrastructure which hampers their reuse and flexibility to changes. In this paper, we present a process-oriented and service-based approach for supporting the development of adaptive sensor-based applications. Our approach decouples application logic from its implementation. A design-time model is first specified, as a flow of activities, which is then deployed in a particular environment. Decoupling the application logic from its implementation enables, on one hand, to foster the reuse at the application level and, on the other hand, to adapt the same application to different environments and situations. We propose also an activity recommendation technique to provide assistance to application designers by recommending to them activities that have been used in a similar compositional context. Our approach has been prototyped using service standards such as BPMN within the context of the VITRO European project and validated by several use cases.

Current approaches for semantic management of business processes and services assume and build on semantic models which don't exist in practice. A key and open research problem is how to lift semantic models from existing process and service descriptions. In this paper, we are interested in extracting action capabilities from their textual descriptions. We first introduce a semantic frame-based capability model that features domain-specific functional properties. We presentan approach for retrieving top-k capabilities that match best a natural language description of an action. Our approach has been evaluated using publicly available process and service descriptions.

Even though the concept of capability is an important element in service oriented architectures and enterprise information systems, little effort has been put towards modelling it as a first class citizen. Major related contributions were part of other efforts such as modelling business processes, service description and search requests. In case of service descriptions, current approaches confuse capabilities with invocation interfaces or do not go beyond the classical IOPEs paradigm. Both approaches do not allow to determine intuitively what the service does. In our work, we are interested in modelling and managing capabilities as stand alone entities, presented via an action verb and a set of domain related attributes. Presenting capabilities as such allows us to represent them at different levels of abstraction and make explicit links between them. These links permit to create a direct acyclic graph. Given this graph, we provide in this paper a heuristic approach for capability discovery. We also present the needed algorithms for building and maintaining such structure.

In recent years, we witness the increasing trend that more applications are developed by composing Web services. Services interact with each other in ways not necessarily foreseen during their development phase. In this setting, mismatches usually exist between services, and adapters are typically synthesized to reconcile mismatches occurring in certain interactions. The technique that identifies the most suitable provider service from a set of functionally equivalent candidates with respect to certain requirements specified by the requester is essential. To address this challenge, we propose a technique called adaptability assessment , which 1) provides a set of conditions that determines when service interactions can be conducted and 2) computes an adaptation degree that specifies to what extent a service protocol is adaptable to another service protocol. Adaptability assessment complements the techniques that synthesize adapters. Specifically, when adaptability assessment suggests that two service protocols can conduct some interactions according to the adaptation mechanisms of a certain adapter and these interactions can fulfill the requester's requirements, then the effort of synthesizing an adapter is beneficial to potential service interactions. As such, the requester can acknowledge whether his/her expected interactions can be conducted or not and under which conditions. This is important before conducting an interaction, particularly when this interaction is critical, long running, and nonrepeatable.

Abstract Given the inherent autonomy, heterogeneity, and continuous evolution of Web services, mismatches usually exist between service protocols. Adapters are typically used to reconcile these mismatches. Before synthesizing an adapter, a service requestor is often willing to assess whether her expected interactions can be conducted or not. The effort of synthesizing an adapter is beneficial only if the result of this assessment is positive. Previous effort analyzing service interactions focused on either (i) compatibility analysis for checking whether interactions can be conducted in a direct manner or (ii) adapter synthesization for reconciling mismatches. In this paper we propose a new kind of adaptability assessment that (i) determines whether two service protocols of a requestor and a provider are adaptable, (ii) computes an adaptation degree, and (iii) identifies conditions that determine when these two service protocols can be adapted. This adaptability assessment provides complementary criteria to the service requestor for selecting a suitable service protocol from a set of functionally equivalent candidates according to her requirements. Copyright © 2010 John Wiley & Sons, Ltd.

Web services are defined independently of any execution context. Due to their inherent autonomy and heterogeneity, it is difficult to examine the behaviour of composite services, especially in case of failures. This paper is interested in ensuring composite services reliability. Reliable composition is defined as a composition where all instance executions are correct from a transactional and business point of view. In this paper, the authors propose a transactional approach for ensuring reliable Web service compositions. The approach integrates the expressivity power of workflow models and the reliability of Advanced Transactional Models (ATM). This method offers flexibility for designers to specify their requirements in terms of control structure, using workflow patterns, and execution correctness. Contrary to ATM, the authors start from the designers’ specifications to define the appropriate transactional mechanisms that ensure correct executions according to their requirements.

Different from process components, Web services are defined independently from any execution context. A key challenge of (Web) service compositions is how to ensure reliable execution. Due to their inherent autonomy and heterogeneity, it is difficult to reason about the behavior of service compositions especially in case of failures. Therefore, there is a growing interest for verification techniques which help to prevent service composition execution failures. In this paper, we propose an event-driven approach to validate the transactional behavior of service compositions. The transactional behavior verification is done either at design time to validate recovery mechanisms consistency, or after runtime to report execution deviations and repair design errors, and therefore, formally ensure service execution reliability. By using the Event Calculus formalism to specify and check the transactional behavior consistency of service composition, our approach provides a logical foundation to ensure service execution reliability.

This paper proposes a formal technique to verify whether or not an expected interaction is adaptable. We first present our observation that a mediated service interaction is synchronizable. This fact is a prerequisite of our approach. Hereafter, we formally model a protocol scenario (i.e., a part of

Web service interoperations have triggered a growing interest in analyzing compatibility and similarity for public processes. However, current approaches are limited since they mainly focus on control-flow but largely ignore data-flow. This ignorance causes that they improperly regard public processes, which can interact with or be replaced by each other with the help of process mediators, as incompatible or different. To address these problems, we propose a novel approach to check compatibility and similarity of public processes considering both control-flow and data-flow. We firstly generate scenarios and views to describe a public process. Then the degree of compatibility and similarity of public processes are computed based on pairwise compatibility or similarity of their views. Our approach will benefit service modelers and users not only for a better understanding of public processes, but also for checking compatibility and similarity of public processes, which will further identify and solve mismatches, and thus facilitate Web service interoperations.

Web service interactions lie in the core of SOA. Due to the autonomy, heterogeneity and continuous evolution of Web services, mediators are usually needed to support service interactions to overcome possible mismatches that may exist among business processes. In this paper, we introduce a space-based architecture for process mediator which considers both control-flow and data-flow, present possible mismatch patterns, and suggest how they can be automatically mediated. Our work can be used to perform runtime mediation and thus to facilitate service interactions.

Control and data dependencies are important information in business processes that supports process modeling, analysis, and execution. However, sequencing constraints, which are prescribed by control structures, obfuscate the true sources of dependencies. In addition, most work improperly equalizes sequencing constraint and control dependency, and regards data dependencies as a flow of data processing relying on sequencing constraints.In this paper, business activities are described with a semantic description that defines precondition, effect, input, and output. Based on which we specify what control and data dependencies are. Control dependencies are related to the precondition and the effect. Mandatory data dependencies are related to the input and the output, while optional data dependencies are derived from possible conditions on business activities. All control and data dependencies are optimized into a minimal dependency graph which captures essential dependencies to be preserved. A sequencing constraint is possibly due to control and/or data dependencies. A clear view on the relation and the difference between sequencing constraint and control/data dependency is crucial to better support process modeling, analysis, and execution.

Due to the inherent autonomy and heterogeneity of Web services, ensuring composite services reliability remains a challenging problem. Extending the classical control flow with a transactional flow (encapsulating a set of recovery mechanisms) is widely accepted for ensuring composite services reliability. However, current approaches define recovery mechanisms in and ad-hoc way while they have to respect consistency rules regarding the control flow. In this paper, we propose a formal model based on event calculus for capturing both control and transactional flow of composite services. Following a pattern based modelling approach, we depict a set of rules characterising consistent transactional flow that can be defined w.r.t a given control flow. In addition, we propose two complementary approaches for enhancing composite services reliability.

Reliability is one of the main challenge that encounter Web servicescompositions. Due to the inherent autonomy and heterogeneity of Webservices it is difficult to predict the behavior of the overallcomposite service.Current related technologies are unable to resolve this problemefficiently. These technologies rely on two existing strongapproa-ches: transactional processing and workflow systems. In onehand transactional processing ensures reliability. However, they aretoo rigid to support process based applications like composite Webservices. On the other hand, workflow systems focus mainly oncoordination and organizational aspects and ignore reliabilityissues.In this paper we propose a new solution that combines the businessprocess adequacy of workflow systems and the reliability oftransactional processing. We introduce the concept of transactionalpatterns to ensure reliable composite services. A transactionalpattern can be seen as a convergence concept between workflowpatterns and advanced transactional models. We show how we use it todefine composite services and how we ensure their reliabilityaccording to the designers specific needs.

One of the main challenges that encounter Web services is how to ensure reliable compositions. In this paper we present an approach that starts from a composite service effective executions to improve its reliability. Basically, we propose a set of mining techniques to discover its model and its transactional behavior from an event based log. Then, based on this mining step, we use a set of rules to improve its recovery mechanisms

The recent evolution of Internet, driven by the Web services technology, is extending the role of the Web from a support of information interaction to a middleware for B2B interactions.Indeed, the Web services technology allows enterprises to outsource parts of their business processes using Web services. And it also provides the opportunity to dynamically offer new value-added services through the composition of pre-existing Web services.In spite of the growing interest in Web services, current technologies are found lacking efficient transactional support for composite Web services (CSs).In this paper, we propose a transactional approach to ensure the failure atomicity, of a CS, required by partners. We use the Accepted Termination States (ATS) property as a mean to express the required failure atomicity.Partners specify their CS, mainly its control flow, and the required ATS. Then, we use a set of transactional rules to assist designers to compose a valid CS with regards to the specified ATS.

Distributed computing applications rely on transmissions of messages between processes. However, as workstations are not intended to manage this kind of communications, it is necessary to use some communication tools known as message passing libraries. Currently, MPI (Message Passing Interface) and PVM (Parallel Virtual Machine) are the most used. In addition, the need for interoperability among the rapidly proliferating amount of hardware and software led to the definition of CORBA (Common Object Request Broker Architecture), which standardizes the execution support of distributed object applications. This architecture offers good interoperability and encapsulation support. Moreover, its method invocation mechanism, offers several features and can be used as a good communication model. Consequently, the use of such an architecture for distributed and grid computing applications seems interesting and promising. However, CORBA is always criticized on the performance level. By taking account of all these elements, a performance evaluation of CORBA seems necessary. The aim of the paper is to present benchmark results of some CORBA implementations (ORBacus and TAO) and to compare them with those of the two message passing libraries MPI (MPICH and LAM) and PVM, by using a Network of WorkStations (NOW).