Service-based Business Processes Research Articles

BPEL process defects prediction using multi-objective evolutionary search

Web services are becoming increasingly popular technologies for modern organizations to improve their cooperation and collaboration through building new software systems by composing pre-built services. Such services are typically composed and executed through BPEL (Business Process Execution Language) processes. Like any other software artifact, such processes are frequently changed to add new or modify existing functionalities or adapt to environmental changes. However, poorly planned changes may introduce BPEL process design defects known as anti-patterns or defects. The presence of defects often leads to a regression in software quality. In this paper, we introduce an automated approach to predict the presence of defects in BPEL code using Multi-Objective Genetic Programming (MOGP). Our approach consists of learning from real-world instances of each service-based business process defect (i.e., anti-pattern) type to infer prediction rules based on the combinations of process metrics and their associated threshold values. We evaluate our approach based on a dataset of 178 real-world business processes that belong to various application domains, and a variety of BPEL process defect types such as data flow and portability defects. The statistical analysis of the achieved results shows the effectiveness of our approach in identifying defects compared with state-of-the-art techniques with a median accuracy of 91%.

Optimal autonomic management of service-based business processes in the cloud

Cloud computing is an emerging paradigm that provides hardware, platform and software resources as services based on pay-as-you-go model. It is being increasingly used for hosting and executing service-based business processes. However, business processes are subject to dynamic evolution during their life-cycle due to the highly dynamic evolution of the cloud environment. Therefore, to efficiently manage them according to the autonomic computing paradigm, service-based business processes can be associated with autonomic managers. Autonomic managers monitor these processes, analyze monitoring data, plan configuration actions, and execute these actions on these processes. The main objective of cloud computing is to improve the performance level while minimizing operating costs. Thus, due to the diversity of business processes requirements and the heterogeneity of cloud resources, discovering the optimal management cost of a business process in the cloud becomes a highly challenging problem. For this purpose, we propose an approach based on an Integer Linear Program to find out the optimal allocation of cloud resources that meet customers’ requirements and resources’ constraints. Besides, to validate our approach under realistic conditions and inputs, we propose an extension of the CloudSim simulator to analyze the cloud resources consumed by an autonomic business process. Experiments conducted on two real datasets highlight the effectiveness and performance of our approach.

Optimizing Autonomic Resources for the Management of Large Service-Based Business Processes

Cloud Computing, as a distributed computing paradigm, consists of the provisioning of infrastructure, platform, and software resources as services. This paradigm is being increasingly used for the deployment and execution of service-based business processes. To efficiently manage them according to the autonomic computing paradigm, service-based business processes can be associated with autonomic managers that monitor these processes, analyze monitoring data, plan configuration actions, and execute these actions on these processes. Although, during these last years, autonomic management of cloud services has received increasing attention, the optimization of autonomic managers to be assigned to cloud services remains not well explored. In fact, almost all the existing solutions on autonomic computing have been interested in modeling and implementing autonomic mechanisms without making any effort to optimize the number of used autonomic managers. Moreover, when it comes to large service-based business processes, optimization of management resources becomes a critical issue. To overcome this issue, we present in this paper a novel approach to determine how many autonomic managers to use for the management of large service-based business processes in order to minimize their cost while avoiding management bottlenecks. Experiments conducted on three different types of datasets highlight the effectiveness of our approach.

An Empirical Study on Data Flow Bugs in Business Processes

An increasing number of service-based business processes are being developed with the booming of BPaaS (Business Process as a Service) in cloud computing. The profits and performance of enterprises strongly depend on the soundness of their processes being bereft of control flow and data flow bugs. Although some work has focused on the detection of control flow bugs, few studies have comprehensively and empirically investigated data flow bugs in business processes. To this end, we report an empirical study on data flow bugs in business (BPEL) processes. Our analysis of 178 real-world BPEL processes reveals that data flow bugs are surprisingly common: 94 BPEL processes involve data flow bugs, among which redundant output is predominant. The distribution and common scenarios of data flow bugs provide a reference for BPEL process designers. We also investigate the correlation between process complexity metrics and data flow bugs. Based on the statistics of the process complexity metrics and data flow bugs in our empirical study, we present a method to select appropriate metrics as features of BPEL processes and utilize state-of-the-art supervised learning algorithms to predict data flow bugs in an unseen BPEL process. The prediction accuracies of the different classification algorithms exceed 90 percent on average when using our selected metrics.

Toward Supporting Unplanned Dynamic Changes of Service-Based Business Processes

Service-oriented architecture (SOA) has become an application development paradigm widely recognized both in academia and in industry. Although SOA-based applications may vertically implement business processes through the composition of loosely coupled services, they have to face frequent changes, such as unavailability of service (due to the uncontrollable, dynamic, and distributed environments) or dynamic replacement of service (due to specific user requirements). This indicates that the service compositions are expected to be adaptable enough to cater to such changing situations. In this paper, we propose an approach to supporting unplanned dynamic changes of service compositions by combining variability management and dynamic binding. The proposed approach introduces the concept of abstract proxy services in a variability-supporting service composition language, namely VxBPEL, and provides a mechanism to support variation design and dynamic binding for unplanned changes at run time. To realize the proposed approach, we have developed a service composition engine that supports abstract proxy services and their run-time replacement via service discovery or user intervention. Finally, a case study has been conducted to demonstrate the feasibility of the proposed approach and quantify the performance overhead resulting from runtime variability management and dynamic binding. The experimental results show that the proposed approach overcomes the limitation of imperative variability-based approaches in handling unplanned dynamic changes and further enhances the dynamic adaptability of VxBPEL-based service compositions.

Change management of service-based business processes

Service-oriented computing paradigm and web service technologies facilitate cross-organizational cooperation. The business processes of involved organizations are referred to as service-based business processes (SBPs). The dynamic nature makes SBPs subject to changes in the internal and external requirements. It is critical to have a method to manage changes in SBPs. In this work, we propose a Petri net-based model with the correctness verification capability for modeling. We also identify a set of SBP change patterns. An SBP change management framework is proposed with a demonstration. Even though the problem of change management has been extensively studied in BPM field and web service field, existing approaches are limited to deal with the diversity of the SBP components and the complexity of the dependencies among these components.

STRATFram: A framework for describing and evaluating elasticity strategies for service-based business processes in the cloud

In the recent years, growing attention has been paid to the concept of Cloud Computing as a new computing paradigm for executing and handling operations/processes in an efficient and cost-effective way. Cloud Computing’s elasticity and its flexibility in service delivery have been the most important features behind this attention which encourage companies to migrate their operation/processes to the cloud to ensure the required QoS while using resources and reduce their expenses. Elasticity management has been considered as a pivotal issue among IT community that works on finding the right tradeoffs between QoS levels and operational costs by developing novel methods and mechanisms. However, controlling process elasticity and defining non-trivial elasticity strategies are challenging issues. Also, despite the growing attention paid to the cloud and its elasticity property in particular, there is still a lack of solutions that support the evaluation of elasticity strategies used to ensure the elasticity of processes at service-level. In this paper, we present a framework for describing and evaluating elasticity strategies for Service-based Business Processes (SBP), called StratFram. It is composed of a set of domain-specific languages designed to generalize the use of the framework and to facilitate the description of evaluation elements that are needed to evaluate elasticity strategies before using them in real cloud environment. Using StratFram, SBP holders are allowed to define: (i) an elasticity model with specific elasticity capabilities on which they want to define and evaluate their elasticity strategies, (ii) a SBP model for which the elasticity strategies will be defined and evaluated, (iii) a set of elasticity strategies based on the elasticity capabilities of the defined elasticity model and for the provided SBP model, and (iv) a simulation configuration which identifies simulation properties/elements. The evaluation of elasticity strategies consists in providing a set of plots that allows the analysis and the comparison of strategies. Our contributions and developments provide Cloud tenants with facilities to choose elasticity strategies that fit to their business processes and usage behaviors.

A survey on automation of security requirements in service-based business processes

Service-oriented computing (SOC) and business process management (BPM) are essential topics in computer science. Companies are widely adopting business process standards, such as BPMN, to model their business processes, while automatise them by using services from the SOC world. The automation leads to a gain of efficiency in executing business processes and facilitates the execution of tests. However, the automation also raises fundamental security concerns, especially considering that it can use external services available on the internet, e.g., web services. For example, companies are not comfortable to use systems that communicate over the internet without guarantees that secure actions have been adequately used. The main objective of this work is to provide a holistic view of current initiatives and tools to model and enforce security requirements in service-based business processes along with open research and practical challenges on this subject. The intention is that this work can serve as a source of theoretical and pragmatic ideas for those who want to execute their business processes having in mind security concerns.

Formal Verification of Temporal Constraints for Mobile Service-Based Business Process Models

Service-based business processes are typically used for achieving business goals through the execution of a set of activities. These activities are usually implemented upon mobile devices in terms of mobile services in a dynamic and pervasive environment. The execution of business processes is recorded in event logs in contemporary enterprise information systems and is discovered, monitored, and improved leveraging process mining techniques. However, process mining from time perspective which has been evolving as an emerging principle for supporting the temporal analysis of these mobile service-based business processes has not been explored extensively. To address this challenge, we propose to extend the mobile service-based business process model on the basis of the specification and verification of temporal constraints. A timed business process model is proposed where the relative and absolute temporal constraints correspond to each individual activity, sets of activities with control relations, and edges between activities or gateways are estimated. Conformance checking is implemented for the verification and improvement of the proposed model with respect to the accuracy, precision, and recall. Extensive evaluations and comparison of our technique with the state of the art are conducted based on publicly available real-life event logs, and the results demonstrate the effectiveness and verification of the proposed model.

An Algebraic Method for Analysing Control Flow of BPMN Models

This paper introduces an approach for formal verification of BPMN models. The incompatible constructs of the BPMN patterns can lead to wrong or incomplete semantics which resulting the behavioral errors such as deadlock and multiple termination. This research is motivated by the need to create a correct business process and in order to generate a more complete formalization of BPMN semantics than existing formalizations. We first introduce the chosen patterns which are the most used in the modelisation of the service-based business processes. Then, we illustrate a definition of the execution semantics of these patterns by using the rules of Max+ Algebra formulas, which have important benefits.

Automation of service-based security-aware business processes in the Cloud

The use of business process standards to model and execute business needs is growing rapidly. In addition, Service-oriented Computing has been adopted to realize business processes, which basically consists of executing the process activities using services available in the Internet. In this context, the importance of security is apparent, because sensitive data sent over the Internet may be accessed by unauthorized third-parties. To prevent security problems, users may associate security requirements that must be enforced in essential tasks of the business process. This fact leads to the need of automation, because both functional and security requirements should be modeled, at high-level, and enforced, at execution level. This work proposes a cloud-based solution named BPA-Sec4Cloud that supports all phases of the security-aware business process automation, from its modeling to its deployment. The use of a cloud-based solution facilitates the deployment process because all needed resources are available in the cloud and ready to be used. In addition, the cloud is also used as a platform in order to provide specific services, such as translators, to support the automation process. In order to evaluate the BPA-Sec4Cloud, the solution was compared against existing solutions through the use of metrics related to the quality of generated artifacts.

A distributed architecture for policy-customisable multi-tenant processes-as-a-service

Service-based business processes are often developed and deployed by single organisations. In distributed, shared resource environments like the cloud on the other hand, consumers share resources owned by cloud providers. This requires multi-tenancy capability for service processes that provide customised behaviour on shared process implementations to meet the varying needs of different process consumers as tenants of the process resource. In this paper, we define a distributed multi-tenant architecture for Business Process Execution Language (BPEL) processes provided as a service. A single-version BPEL process is deployed by a provider and offered for all process consumers, combined with a customisation and management functionality to create a unique experience for different consumers (process tenants). We provide two core components: a policy model for consumers to express customisation/business requirements of service processes and a coordination framework for policy enforcement between consumers and providers to achieve on-the-fly customisation of service processes.

An autonomic approach to manage elasticity of business processes in the Cloud

Cloud Computing is gaining more and more importance in the Information Technologies (IT) scope. One of the major assets of this paradigm is its economic model based on pay-as-you-go model. Cloud Computing gets more attention from IT users when it fits their required QoS and reduces their expenses. This task cannot be done without increasing the autonomy of the provisioned Cloud resources. In this paper, we propose a holistic approach that allows to dynamically adding autonomic management facilities to Cloud resources even if they were designed without these facilities. Based on the Open Cloud Computing Interface (OCCI) standard, we propose a generic model that allows describing the needed resources to render autonomic a given Cloud resource independently of the service level (Infrastructure, Platform or Software). Herein, we define new OCCI Resources, Links and Mixins that allow provisioning autonomic Cloud Resources. In order to illustrate our approach, we propose a use case that specializes our autonomic infrastructure to ensure the elasticity of Service-based Business Processes (SBPs). The elasticity approach that we are using is based on a formal model that features duplication/consolidation mechanisms and a generic Controller that defines and evaluates elasticity strategies. To validate our proposal, we present an end to end scenario of provisioning an elastic SBP on a public PaaS. Evaluation of our approach on a realistic situation shows its efficiency.

Research on Adaptation of Service-based Business Processes

This paper proposes an adaptation mechanism based on adaptation planning graph for service-based business processes. First, a three-layer representation model of service-based business process is introduced. Second, control-flow patterns of tasks, goal, logic model of service-based business process and adaptation planning graph are introduced to enforce reliability of composite web services at run-time. Finally, a simulation example of adaptation in service-based business processes is given. Simulations prove that this approach can efficiently guarantee the reliability of composite services at run-time. DOI : http://dx.doi.org/10.11591/telkomnika.v12i1.4148

Towards a model-driven approach for treating quality attributes of service-based business processes

A systematic way for treating non-functional quality attributes into the business process management lifecycle is still a challenge. The agnostic, integrated and automated treatment of these attributes from the most abstract business level to their technical realisation at execution level is a complex task. In this context, this paper presents a model-driven approach centred on quality attributes of business processes. Additionally, two key characteristics of our approach are the agnostic treatment of the quality attribute being considered and its projection on standards such as user requirement notation URN, UML for QoS and WS-Policy. To illustrate the proposed approach, a supply chain management use case is used. Finally, in order to evaluate the model-driven approach, an evaluation plan based on goal/question/metric GQM is defined, providing the rationale to define and to apply evaluation metrics of interest.

Enforcement of entailment constraints in distributed service-based business processes

ContextA distributed business process is executed in a distributed computing environment. The service-oriented architecture (SOA) paradigm is a popular option for the integration of software services and execution of distributed business processes. Entailment constraints, such as mutual exclusion and binding constraints, are important means to control process execution. Mutually exclusive tasks result from the division of powerful rights and responsibilities to prevent fraud and abuse. In contrast, binding constraints define that a subject who performed one task must also perform the corresponding bound task(s). ObjectiveWe aim to provide a model-driven approach for the specification and enforcement of task-based entailment constraints in distributed service-based business processes. MethodBased on a generic metamodel, we define a domain-specific language (DSL) that maps the different modeling-level artifacts to the implementation-level. The DSL integrates elements from role-based access control (RBAC) with the tasks that are performed in a business process. Process definitions are annotated using the DSL, and our software platform uses automated model transformations to produce executable WS-BPEL specifications which enforce the entailment constraints. We evaluate the impact of constraint enforcement on runtime performance for five selected service-based processes from existing literature. ResultsOur evaluation demonstrates that the approach correctly enforces task-based entailment constraints at runtime. The performance experiments illustrate that the runtime enforcement operates with an overhead that scales well up to the order of several ten thousand logged invocations. Using our DSL annotations, the user-defined process definition remains declarative and clean of security enforcement code. ConclusionOur approach decouples the concerns of (non-technical) domain experts from technical details of entailment constraint enforcement. The developed framework integrates seamlessly with WS-BPEL and the Web services technology stack. Our prototype implementation shows the feasibility of the approach, and the evaluation points to future work and further performance optimizations.

SOA-enabled compliance management: instrumenting, assessing, and analyzing service-based business processes

Facilitating compliance management, that is, assisting a company's management in conforming to laws, regulations, standards, contracts, and policies, is a hot but non-trivial task. The service-oriented architecture (SOA) has evolved traditional, manual business practices into modern, service-based IT practices that ease part of the problem: the systematic definition and execution of business processes. This, in turn, facilitates the online monitoring of system behaviors and the enforcement of allowed behaviors--all ingredients that can be used to assist compliance management on the fly during process execution. In this paper, instead of focusing on monitoring and runtime enforcement of rules or constraints, we strive for an alternative approach to compliance management in SOAs that aims at assessing and improving compliance. We propose two ingredients: (i) a model and tool to design compliant service-based processes and to instrument them in order to generate evidence of how they are executed and (ii) a reporting and analysis suite to create awareness of a company's compliance state and to enable understanding why and where compliance violations have occurred. Together, these ingredients result in an approach that is close to how the real stakeholders--compliance experts and auditors--actually assess the state of compliance in practice and that is less intrusive than enforcing compliance.

Exception Handling in Service-Based Business Processes by Applying Adaptation Planning Graph

This paper proposes an exception handling mechanism based on Adaptation Planning Graph for service-based business processes. A three-layer representation model of service-based business process is introduced firstly. And then, Logic Model of Service-based Business Process and Adaptation Planning Graph are introduced to enforce reliability of composite Web Services at run-time. Simulations prove that this approach can efficiently guarantee the reliability of composite services at run-time.

An Exception Handling Approach for Service-Based Business Processes

This paper proposes an exception handling mechanism for running reliable service-based business processes. With Smart Process-based Application Model that we have proposed, a smart process is generated automatically according to the execution of composite web services to better meet user’s individual requirements. However, the loosely-coupled nature of the smart process introduces more exceptions during its running. This paper will mainly focus on the failures of a smart process, and give an approach to handle exceptions. Based on Execution Transition Diagram(ETD) and several execution states we define in this paper, exceptions can be handled automatically by selecting rational transitions in the ETD during the execution of a smart process.

Evolutionary Approach to Development of Collaborative Teleconsultation System for Imaging Medicine

This paper presents an evolution of a modern collaborative teleconsultation system called TeleDICOM over the period of several years. We show how new features (required from a medical point of view) can be provided, which barriers have been identified, and how these factors influence the system's architecture. A turning point in the evolution of our system was the formulation of a new architecture, fully facilitating service-oriented architecture paradigm guidelines. We therefore show how the knowledge and experience gathered during utilization of previous versions of TeleDICOM positively stimulate procedures of service-based system decomposition and business processes definition.