Some companies are willing to execute their business processes (BP) in the cloud for enjoying its benefits. However, they are also reluctant because of the new security risks that using cloud resources introduces. Security risk includes many dimensions, but this work focus on preserving the privacy of the logic of a BP deployed in a multi-cloud context by preventing a coalition of malicious clouds to re-construct important information from this logic. More precisely, the paper presents a BP logic privacy metric directly supporting the evaluation of the risk a company has its logic hacked in a particular multi-cloud configuration.

Companies are ready to outsource their business process to the cloud to enjoy its benefits. However they must be sure that their business know-how is preserved. Although some solutions already exist and consist in splitting the model into a collaboration of BP fragments for a deployment in a muti-cloud context, none of them takes into account the possibility of collusion between the clouds executing the different fragments. To address this issue, we propose in this paper a solution consisting in adding fake BP fragments at specific locations in the process, so as to complicate its structure and hide the direct interaction between clouds executing sensitive fragments. Therefore, the discovery of the process by malicious cloud providers is delayed. The approach is validated against an introduced metric. It demonstrates that our approach is better in the worst case than previous approaches in best cases.

Business process (BP) stakeholders want to enjoy the benefits of the cloud, but they are also reluctant to expose their BP models which express the know-how of their companies. To prevent such a know-how exposure, this paper proposes a design-time approach for transforming a BP model into BP fragments so that these BP fragments externalized in a multi-cloud context do not allow a cloud resource provider to understand a critical fragment of the company. While existing contributions on this topic remain at the level of principles, we propose an algorithm supporting automatically such a BP model transformation.

In this paper, we propose an approach for deploying business processes on the cloud supporting security constraints, thereby ensuring sensitive data exchange. This approach uses partitionning techniques for fulfilling security requirements and optimizing communication costs. The partitions are deployed independently on different cloud platforms. Subsequently, these partitions depend on message exchange synchronization, which defines our choreography on the cloud. Moreover, we consider additional requirements related to data-dependencies and Quality of Service (QoS) disparities to optimize the execution of the outsourced process. Our approach is motivated by an insurance case study and implemented within an open source cloud platform.

It is recognized that the most important obstacle to the development of the cloud is the variety of new security threats which requests new methods and mechanisms. This is even truer for those who want to deploy business processes, because of the critical knowledge they encapsulate in terms of know-how and data. This paper proposes an approach combining modeling techniques and cloud selection for a trusted deployment of a security risk-aware business process in security constrained clouds.

The Cloud computing paradigm is adopted for its several advantages like reduction of cost incurred when using a set of resources. Despite the many proven benefits of using a Cloud infrastructure to run business processes, it is still faced with a major problem that can compromise its success: the lack of guidance for choosing between multiple offerings. To ensure this, we propose a set of algorithms for business process scheduling in Cloud computing environments. More precisely, we propose an extension of our previous approaches taking into account the fact that several instances of the same process can run simultaneously, and they may have to share the same resources. The proposed approaches take into account the Cloud elasticity feature on the one hand, and on the other hand, they consider the two most important quality of service criteria when running business process in Clouds environment, namely (i) the overall execution time and (ii) the cost incurred using a set of resources. In addition they allow to ensure fairness between the different concurrent business process instances.

Although there are few efficient algorithms in the literature for scientific workflow tasks allocation and scheduling for heterogeneous resources such as those proposed in grid computing context, they usually require a bounded number of computer resources that cannot be applied in Cloud computing environment. Indeed, unlike grid, elastic computing, such asAmazon's EC2, allows users to allocate and release compute resources on-demand and pay only for what they use. Therefore, it is reasonable to assume that the number of resources is infinite. This feature of Clouds has been called âillusion of infiniteresourcesâ. However, despite the proven benefits of using Cloud to run scientific workflows, users lack guidance for choosing between multiple offering while taking into account several objectives which are often conflicting. On the other side, the workflow tasks allocation and scheduling have been shown to be NP-complete problems. Thus, it is convenient to use heuristic rather than deterministic algorithm. The objective of this paper is to design an allocation strategy for Cloud computing platform. More precisely, we propose three complementary bi-criteria approaches for scheduling workflows on distributed Cloud resources, taking into account the overall execution time and the cost incurred by using a set of resources.

A workflow process defines a set of activities and the specific order according to which they should be executed in order to achieve a common objective. The correctness and efficiency of the business process supported by the workflow management are vital, in particular the k-soundness property when processes are modeled by workflow nets (WF-nets). This property entails the proper termination of the workflow execution and the absence of tasks that do not contribute to the processing cases. Furthermore, business processes are not isolated and in order to support the global performance of a given organization, they should well articulated, and correctly synchronized to each other. Nevertheless, without specific conditions, the k-soundness criterion is not compositional while it should remain valid for the set articulated processes. We propose in this paper a set of compositional rules that allow to build complex workflows from single ones while preserving k-soundness property under elementary conditions. Moreover, for the free-choice Petri net class we show that the soundness property verification can be efficiently checked.

Resources allocation and scheduling has been recognised as an important topic for business process execution. However, despite the proven benefits of using Cloud to run business process, users lack guidance for choosing between multiple offering while taking into account several objectives which are often conflicting. Moreover, when running business processes it is difficult to automate all tasks. In this paper, we propose three complementary approaches for Cloud computing platform. On the other side, elastic computing, such as Amazon EC2, allows users to allocate and release compute resources (virtual machines) on-demand and pay only for what they use. Therefore, it is reasonable to assume that the number of virtual machine is infinite while the number of human resources is finite. This feature of Clouds has been called “illusion of infinite resources”. In this paper, we design an allocation strategy for Cloud computing platform taking into account the above characteristics. More precisely, we propose three complementary bi-criterion approaches for scheduling business process on distributed Cloud resources.

Cross-organizational service-based processes are increasingly adopted by different companies when they can not achieve goals on their own. In order to guarantee that all involved partners are informed about errors that may happen in the collaboration, it is necessary to monitor the execution process by continuously observing and checking message exchanges during runtime. This allows a global process tracking and evaluation of process metrics. In this paper, we present an approach for decentralized monitoring of cross-organizational choreographies. We introduce the concept of External Flow Monitoring and define a hierarchical propagation model for exchanging external notifications between the collaborating parties. We also introduce the concept of EFM-view which allows partners to track the state of the choreography beyond their own processes. The collected monitoring data can be further used for the evaluation of global process metrics by expressing and evaluating statistical queries over execution traces.

In this paper, we propose an approach for the verification of declarative Web services composition processes using satisfiability solving. The need for the satisfiability solving approach stems from the nature of declarative processes which are defined by only specifying the constraints that mark the boundary of the solution to the composition process. As a result the state space of a declarative process can be significantly large, as the process is only partially defined and all the transitions have not been explicitly defined. Further, as the conflict clauses returned by the SAT solver can be significantly large for complex processes and verification requirements, we propose a filtering criteria and defined patterns for identifying the clauses of interest for process verification.

Every company wants to improve the way it does business, or produce things more efficiently, and make greater profit. Therefore, business processes have become subject to evolutionary changes, which in turn increase the need for an efficient change support. In this sense, many researches were conduc

The usage of the Service Oriented Architecture (SOA) along with the Business Process Management has emerged as a valuable solution for the complex (business process driven) system engineering. With a Model Driven Engineering where the business process models drive the supporting service component architectures, less effort is gone into the Business/IT alignment during the initial development activities, and the IT developers can rapidly proceed with the SOA implementation. However, the difference between the design principles of the emerging domain-specific languages imposes serious challenges in the following re-design phases. Moreover, enabling evolutions on the business process models while keeping them synchronized with the underlying software architecture models is of high relevance to the key elements of any Business Driven Development (BDD). Given a business process update, this paper introduces an incremental model transformation approach that propagates this update to the related service component configurations. It, therefore, supports the change propagation among heterogenous domain-specific languages, e.g., the BPMN and the SCA. As a major contribution, our approach makes model transformation more tractable to reconfigure system architecture without disrupting its structural consistency. We propose a synchronizer that provides the BPMN-to-SCA model synchronization with the help of the conditional graph rewriting.

In this paper, we propose an event-based framework that allows to specify and reason about the monitoring properties during composition process execution. The proposed approach is highly expressive and allows to specify monitoring properties that can be based on either functional or non-functional requirements, allows multi-level detection of any violation, allows to calculate effects of any such violation on the overall process execution and to recover from it using a set of recovery actions. The choice of a reasoning based approach allows to foresee the effects of violations and respects any functional and non-functional constraints associated with the process, when performing recovery. In addition, as the approach builds upon an event-based declarative framework called DISC, it results in an integrated approach as both composition design and monitoring framework are event-based.

Task delegation presents one of the business process security leitmotifs.It defines a mechanism that bridges the gap between workflow and access control systems.Delegation completion and authorisation enforcement are specified under specific constraints so-called events.In this article, we aim to reason about delegation events to model task delegation and to specify delegation policies using a logical framework.To that end, we propose an event-based task delegation model to control the delegation execution.We then identify relevant events responsible for the dynamic enforcement of delegation policies.Further, we define a task-oriented access control model to specify delegation constraints into authorisation policies.Finally, we propose a technique to automate the delegation policies integration.Using event calculus, we develop a reasoning tool to control the delegation execution and to increase the compliance of all delegation changes in the existing policy of the workflow.

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.

Composite services are usually specified by means of orchestration models that capture control and data-flow relations between activities. Concrete services are then assigned to each activity based on various criteria. In mainstream service orchestration platforms, the orchestration model is execute

Web services composition design, verification and monitoring are active and widely studied research directions. Little work however has been done in integrating these related dimensions using a unified formalism. In this paper we propose a declarative event-oriented framework, called DISC, that serves as a unified framework to bridge the gap between the process design, verification and monitoring. Proposed framework allows for a composition design to accommodate various aspects such as data relationships and constraints, Web services dynamic binding, compliance regulations, security or temporal requirements and others. Then, it allows for instantiating, verifying and executing the composition design and for monitoring the process while in execution. The effect of run-time violations can also be calculated and a set of recovery actions can be taken, allowing for the self-healing Web services composition.

SOA have been deployed as a mean to offer a better flexibility, to increase efficiency through reuse of services and also to improve interoperability by providing new opportunities to connect heterogeneous platforms. However, those benefits make security more difficult to control. Fortunately, new standards are proposed to treat this issue, but their current use makes the architecture much more complex and challenges the characteristics of SOA. In this paper, we address this issue by separating security services from business ones and organizing the architecture referring to the principle of separation of concerns. Next, we propose a new model which consists of three components: business services, security meta-services and an orchestration service. Then, we show that the architecture remains secure while enforcing its flexibility and agility.

Web service paradigm and related technologies have provided favorable means for the realization of collaborative business processes. From both conceptual and implementation points of view, the business processes are based on a centralized management approach. Nevertheless, it is very well known that

Web service paradigm and related technologies have provided favorable means for the realization of collaborative business processes. From both conceptual and implementation points of view, the business processes are based on a centralized management approach. Nevertheless, it is very well known that the enterprise-wide process management where processes may span multiple organizational units requires particular considerations on scalability, heterogeneity, availability and privacy issues, that in turn, require particular consideration on decentralization. In this paper, our aim is to reconcile the decentralization of processes as a step towards the enterprise-wide solutions. We propose a methodology for transforming a centralized process specification into a form that is amenable to a distributed execution and to incorporate the necessary synchronization between different processing entities. The proposed technique has the advantage of being flexible that it computes the abstract constructs and provides a generalized approach to the decentralization of processes.

Web services are the main pillar of the Service Oriented Computing (SOC) paradigm which enables the application integration within and across business organizations. One of the important features of the Web services is the choreography aspect which allows to capture collaborative processes involving multiple services. In this context, one of the important investigations is the choreography compatibility analysis. We mean by the choreography compatibility the capability of a set of Web services of actually interacting by exchanging messages in a proper manner. Whether a set of services are compatible depends not only on their sequences of messages but also on quantitative properties such as timed properties. In this paper, we investigate a model checking based approach that deals with checking the compatibility of a choreography in which the Web services support asynchronous timed communications. Particularly, in this paper we are using the model checker UPPAAL. We propose a set of required abstractions that allow to use the model checker UPPAAL to deal with timed asynchronous communicating services.

Notice of Plagiarism: This paper has been suppressed because it was found to plagiarize the following earlier works:

Web service composition enables businesses to compile value-added services from elementary ones to build new complex services. Usually, Web service composition is needed when a client request cannot be fulfilled by one elementary service. In this paper, we propose a client data flow-tailored composition. The client request is defined by the sequences of data flow the client can provide and the sequences of data flow the client claims. Then, according to the client request, by defining the set of the available services, we aim at combining the services with the client request so that this later is satisfied.

WSBPEL opens up the possibility of applying a range of formal techniques to the verification of Web service behaviors from two points of view: constraints between activities within the same process and dependencies between activities of different processes. In a previous work, we have described an approach for the verification of Web service compositions defined by a set of BPEL processes. The key aspect of such a verification task is the model adopted for representing the communications among the services participating to the composition. In this paper, we propose to extend this approach to handle dependencies between activities of different process orchestrations through message exchanges. Our aim is to enable supporting models of service choreography with multiple interacting Web services compositions, from the perspective of a collaborative distributed composition development environment. The process of behavior analysis moves from a single local process to that of modelling and analyzing the behavior of multiple processes across composition domains.

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.

In very recent times, organisations have started to shift their focus from highly standardised operational business processes (BPs) to other types of processes that cannot be easily replicated due to the knowledge, skills and creativity of people involved. Consequently the field of business process management (BPM) has gradually evolved to include four different, but equally important components: strategy, people, processes and technology. The renewed interest in process-related knowledge and collaboration has opened a new case for possible synergy of BPM and CSCW (computer supported cooperative work) fields. The paper argues that the key to this synergy is in the field of knowledge management. The paper introduces the knowledge dimension of BPs and uses it to determine how collaborative processes, in particular practice-oriented creative BPs, differ from other types of organizational processes. The paper argues that in the case of these BPs, process support needs to co-evolve with process execution itself, and therefore could be also considered as an ever evolving, ldquoorganicrdquo system, creating a new set of interesting research and practical challenges in the future.

This paper reports on a new formal approach for the decentralized orchestration of service oriented processes. We focus on the dynamic binding (discovery and use) of services following a decentralized approach. We investigate synchronization issues of a process being executed on different computing entities. We propose formal techniques that insures the synchronization of distributed activities in the presence of decentralized and dynamic service bindings. Precisely, our contribution consists of two different techniques that prevent concurrent service bindings. The latter are characterized by additional operations implemented by orchestrated services.

Current Web services composition proposals, such as BPML, WSBPEL, WSCI, and OWLS, provide solutions for describing the control and data flows in Web service composition. However, such proposals remain at the descriptive level, without providing any kind of mechanisms or tool support for analysis and verification. Therefore, there is a growing interest for the verification techniques which enable designers to test and repair design errors even before actual running of the service, or allow designers to detect erroneous properties and formally verify whether the service process design does have certain desired properties. In this paper, we propose to verify Web services composition using an event driven approach. We assume Web services that are coordinated by a composition process expressed in WSBPEL and we use event calculus to specify the properties and requirements to be monitored.

Availability of a wide variety of Web services over the Internet offers opportunities of providing new value added services built by composing them out of existing ones. By integrating individual existing Web services the technology enables the provision of advanced and sophisticated services, such as allowing users to use different types of resources and services simultaneously in a simple procedure. However the management and maintenance of a large number of Web services is not easy and, in particular, needs appropriate authorization policies to be defined so as to realize reliable and secure Web Services. The required authorization policies can be quite complex, resulting in unintended conflicts, which could result in information leaks or prevent access to information needed. This paper proposes a logic based approach using for specifying authorization policies and detecting conflicts resulting from the combination of various kinds of authorization and constraint policies used in Web services environments. The method not only enables static detection of policy conflicts but also yields information that is helpful for correcting the policies. An automated induction-based theorem prover SPIKE is used as verification back-end.

Decentralized execution settings are primordial for most processes where process participants are required to establish P2P interactions. This is particularly true for processes that subject the composition of services advertising different information flow policies. To provide a systematic approach to manage the information flow between composed services, we present a methodology that derives cooperating distributed processes of a centralized specification with respect to their information flow policies. Our contribution shows how service compositions, that cannot be realized with centralized orchestrations or inconsistent choreographies, can be realized with equivalent decentralized executions in an inexpensive and in a reasonable manner.

Managing cooperation in business processes still represents a challenge because of several problems. Concurrent access to common data, coherence of the results, organisation and cooperation correctness are some of them. Looking at isolation problems in the database world and at their solutions using SQL isolation levels, we try to adapt them to the cooperative dimension of processes. In this paper, we identify the phenomena that happen during cooperation in business processes. Then we propose a solution based on isolation spheres to ensure correctness of cooperative processes and customise the exclusion control of the different cooperation phenomena

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.

In this paper we present a process management technology for the coordination of creative and large scale distributed processes. Our approach is the result of usage analysis in domains like Software Development, Architecture/Engineering/Construction, and e-Learning processes. The basic conclusions of these experiments are the following: (1) cooperative processes are described in the same way as production processes, but these descriptions are interpreted in a different way depending on the nature of the process, (2) the interpretation of process description depends mainly on the required flexibility of control flow and of data flow, and on the relationship between them, (3) the management of intermediate results is a central feature for supporting the cooperation inherent to these processes. COO-flow is a process technology that results from these studies. It is based on two complementing contributions: anticipation that allows succeeding activities to cooperate, and COO-transactions that allows parallel activities to cooperate. This paper introduces COO-flow characteristics, gives a (partial) formalization and briefly discusses its Web implementation.

Current workflow models are mainly concerned with the automation of administrative and production business processes. These processes coordinate well-defined activities which execute in isolation, i.e. synchronize only at their start/terminate states. If these models can be applied efficiently for a class of applications, they show their limits when one wants to model the subtlety of cooperative interactions as they occur in more creative processes, typically co-design and co-engineering processes. In this paper, we introduce the concept of cooperative workflow, i.e. a workflow model which extends classical workflow models with capabilities to synchronize activities interacting not only when they start and when they terminate, but also at any point of their execution. In the spirit of the workflow approach, the modelling and enactment of cooperative workflows must remain simple.

The development of large software is always done by teams of people working together and struggling to produce quality software within their budget. Each person in these teams generally knows his job and wants to do it, without being bothered by other people. However, when people work towards a common goal they have to exchange data and create dependencies between each other regarding these data. If these people have to follow a process, cooperating and synchronizing with co-workers and trying to reach one's own goal becomes too difficult to manage. This may lead to frustration, lower productivity and reluctancy to follow the predefined process. This is why some support is needed to avoid common mistakes that occur when people exchange data. In this paper, a hybrid approach to support cooperation is presented. The originality of this approach is the ability to enforce general properties on cooperative interactions while using the semantic of applications to fit particular situations or requirements. This paper gives a brief idea about the general enforced properties on activity interactions. It describes in detail the semantic rules that control activity results, the impacts of the cooperation on these rules and how both dimensions interact.

Previous studies have led to a better understanding of the nature, the characteristics, and the implications of software process modeling and enacting. The authors attempt to reap the benefits of this better understanding, through an analysis of what should be a complete assisted development, in order to deduce a rich set of requirements and facilities for software process modeling and enacting, and to highlight and discuss some essential issues for the improvement of present proposals in the field of model driven IPSEs (integrated project support environments). Three well-known prototypes of assisted environments are examined: TRIAD/CML for the imperative approach, Marvel for the rule-based approach, and IPSE 2.5 for the object-oriented approach. Finally, the authors emphasize essential issues for future third-generation IPSEs: these new IPSEs must be real IPSEs, they must provide multiform assistance and cope with different kinds of processes including complex ones, and they must take into account dynamic evolution of software process models.>