基于Web服务面向虚拟企业的柔性工作流管理技术研究

虚拟企业中盟员和其提供的服务是动态变化的．文中提出将工作流过程模型描述的活动规范中包含一个或多个Web服务请求，通过引入Web服务和Web服务请求的定义和约束，在活动实例的执行过程中实现Web服务请求与最佳Web服务提供企业动态的服务绑定和调用，由于虚拟企业内部的变化不会影响到各盟员业务过程的正常运行，因此具有较高的柔性和自适应性．     

Is that authentic or artificial? Understanding consumer perceptions of risk in e‐service encounters

Abstract. As companies race to digitize physical-based service processes repackaging them as online e-services, it becomes increasingly important to understand how consumers perceive the digitized e-service alternative. We theorize that consumers often perceive e-services as being artificial and non-authentic, and that consumers must perform this assessment when deciding whether new e-services are viable alternatives to traditional service methods. This research investigates whether consumer perceptions of artificiality increase perceptions of e-service risk, which has been shown to hamper consumer acceptance in a variety of online settings. An empirical study operationalized perceived artificiality (PA) within a controlled laboratory experiment that manipulated the risk of a specific e-service class (e-payments). For a specific e-service brand, PA is reduced when the web interface is viewed as easy to use; alternatively, PA is increased when consumers have relatively high risk perceptions about the overall e-service class. Furthermore, consumers who were rated as information technology innovators had lower overall artificiality perceptions, however, exposure to negatively framed e-service efficacy information removed this artificiality reducing effect. The theoretical linkages between PA and perceived risk, and the two antecedents – ease of use and e-service class risk – were confirmed by survey results. The implications of these results for future research as well as the design and marketing of e-services are examined.     

Pattern-based e-service modelling for virtual service enterprises

Business services are customisable, interactive processes that providers have the potential to carry out together with clients that benefit from the effects. It is understood that business service transactions are best organised by means of virtual networks, where information technology allows for configuring multiple providers and processes on a per-request basis. Existing conceptual models for virtual service enterprises (VSEs) propose business service virtualisation for flexible and agile regulation and control of coordination between multiple providers and clients. In this paper, we present an approach for realising business service virtualisation based on software service technology. In particular, we propose a service-oriented software architecture for representing virtual business service processes as e-services. E-service models specify flexible business service interactions between multiple providers and clients of virtual service enterprises and allow for regulation and enforcement of their coordination. We demonstrate the utilisation of our e-service SOA in the context of an e-science scenario, where we show how to design e-service models for the use case of virtual polymorph prediction laboratories.     

Workflow View Driven Cross-Organizational Interoperability in a Web Service Environment

Workflow technology has recently been employed not only within businesses but also as a framework for implementing e-services over the Internet. Such e-services typically require collaborative enactment of workflows across multiple organizations. In this paper, we propose the use of workflow views as a fundamental support mechanism for the interoperability of multiple workflows across business organizations. We present a meta-model of workflow views and their semantics using a cross-organization workflow example based on a supply-chain e-service. We also formulate an interoperation model of workflow views and its consistency criteria. Finally, this paper presents an implementation of the model based on XML and contemporary Web services technologies, with adaptation to our E-ADOME workflow engine.     

Dynamic and adaptive composition of e-services

The Web is rapidly becoming the platform through which many companies deliver services to businesses and individual customers. The number and type of on-line services increase day by day, and this trend is likely to continue at an even faster pace in the immediate future. Examples of e-services currently available include bill payment, delivery of customized news, or archiving and sharing of digital documents. E-Services are typically delivered individually. However, the e-service market creates the opportunity for providing value-added, integrated services, which are delivered by composing existing e-services. To support organizations in pursuing this business opportunity we have developed eFlow, a system that supports the specification, enactment, and management of composite e-services, modeled as processes that are enacted by a service process engine. Composite e-services have to cope with a highly dynamic business environment in terms of services and of service providers. In addition, the increased competition forces companies to provide customized services to better satisfy the needs of every individual customer. Ideally, service process should be able to transparently adapt to changes in the environment and to the need of different customers with minimal or no user intervention. In addition, it should be possible to dynamically modify service process definitions in a simple and effective way to manage cases where user intervention is indeed required. In this paper we show how eFlow achieves these goals.     

Cross-Organizational Transaction Support for E-Services in Virtual Enterprises

In recent years, workflow management systems have become an accepted technology to support automation in process-centric environments. Lately, organizations concentrate more and more on their core business processes while outsourcing supporting processes to other organizations, thereby forming virtual enterprises. The organizations forming the virtual enterprise operate in a B2B e-commerce setting in which provider organizations perform e-services for consumer organizations. To apply workflow management technology in these virtual enterprises, current workflow management systems need to be extended to offer support for cross-organizational processes. Transaction support, already considered an important issue in intra-organizational workflow management systems, must be extended to deal with the cross-organizational aspects as well. This paper presents a high-level, compensation based transaction model and a flexible architecture to support thistransaction model, as required by cross-organizational workflow processes. Characteristic of the model is the flexibility in rollback semantics by combining rollback modes and rollback scopes. This is supported by a dynamically composed architecture that is configured using the agreements that are specified in an electronic contract that has been established between the participating organizations. The transaction model supported by the dynamically composed architecture is implemented in a prototype system, based on commercial workflow management technology.     

Performance implications of information-value offering in e-service systems: Examining the resource-based perspective and innovation strategy

This research examines the performance implications of information-value offering in e-service systems. Specifically, this study introduces both a resource-based perspective that combines technology, human, and business resources to develop an e-service capability, and an innovation strategy that emphasizes service innovation orientation to examine information-value offering. This study also examines how firms bundle e-service capability and service innovation orientation to enhance information-value offering that enhances customer relationships and organizational performance. The results from a survey of 115 financial service firms in Taiwan highlight the importance of how e-service capability and service innovation orientation leads to information-value offering and that this value is shown to positively influence organizational performance by customer relationship performance. The results suggest that researchers and practitioners should pay special attention to the complementary resource-strategy that are needed to successfully implement e-service systems initiatives and that an emphasis on the resource or strategy alone may not be sufficient.     

Transforming e-services evaluation data into business analytics using value models

The rapidly increasing penetration and use of the Internet, in conjunction with the explosion of various technologies based on it, gave rise to the development of numerous e-services, such as e-business, e-banking, e-government and e-learning ones. The websites providing these e-services collect large amounts of users’ activity and evaluation data. It is necessary to transform these data into useful business analytics that allow a better understanding of the strengths and weaknesses of the e-service, the various types of value it generates, and its whole value generation mechanism, and at the same time provide guidance for its improvement and optimization. We propose and validate a methodology for transforming user evaluation data into useful business analytics, founded on the technology acceptance model, the IS success model and e-services. We define a three-layer value model for e-services, including concerning its efficiency, effectiveness and impact on users’ future behavior respectively. This value model is used for collecting and processing service evaluation data from users. We calculated two classes of business analytics: average users’ ratings to identify strengths and weaknesses of e-services; and the impacts of first- layer value measures on the second and third layer value ones. The latter allows a better understanding of the value generation mechanism for e-services and identification of improvement priorities. Our methodology has been applied and validated for an e-learning service provided by a university to technology professionals.     

Process-Based E-Service Composition for Modeling and Automating Zero Latency Supply Chains

E-services are teams of applications and humans (participating electronically) that work together to provide a service or a product. Virtual Enterprises (VEs) are business or organizations that provide products or services that are created and managed by combining and wrapping e-services provided by multiple independent enterprises. To operate efficiently VEs must form supply chains that utilize and manage e-services. In this paper, we propose a Service Oriented Process model (SOP) and describe the architecture and the basic design principles of the Collaboration Management Infrastructure (CMI), a system that supports SOP. SOP permits modeling of e-services and provides for e-service integration to construct efficient multi-enterprise supply chains. This is accomplished by modeling composite e-services as Multi-Enterprise Processes (MEPs). In particular, SOP supports service activities for modeling the services themselves, primitives for composing supply chains from services, and primitives for automating service coordination as required by a supply chain. The CMI system implements SOP and uses a semantic broker that has knowledge about the service capabilities an quality. Therefore, a MEP (and hence its supply chain) is capable of on-the-fly choice of the service providers that are best suited to its objectives (e.g., cheapest or fastest).     

Understanding trust and perceived usefulness in the consumer acceptance of an e-service: a longitudinal investigation

E-services remain characterised by uncertainty despite their proliferation. Consumer trust beliefs are therefore considered an important determinant of e-service adoption. However, the research has not yet considered the potentially dynamic nature of these trust beliefs or how early-stage trust might influence later-stage adoption and use. To address this gap, this study draws on the theory of reasoned action and expectation–confirmation theory in a longitudinal study of trust in e-services. We examine how trust interacts with other consumer beliefs such as perceived usefulness (PU) and how these beliefs together influence consumer intentions and behaviours concerning e-services at both the initial and latter stages of use. The empirical context is online health information services. Data collection on a student population occurred during two time periods approximately five weeks apart. The results show that PU and trust are important at both the initial and latter stages in the consumer acceptance of online health services. Consumers’ actual usage experiences modify perceptions of usefulness and influence the confirmation of their initial expectations. These results have implications for our understanding of the dynamic nature of trust and PU as well as their roles in the long-term sustainability of e-services.     

Development of an adoption model to assess user acceptance of e-service technology: E-Service Technology Acceptance Model

With remarkable growth of ICT development and the Internet popularity, the widespread use of the electronic service is becoming inevitable. Furthermore, as the user adoption plays an important role for successful and effective implementation of any project, thus, there is a need to assess user acceptance of the e-service technology. This research developed the E-Service Technology Acceptance Model (ETAM) to assess the user acceptance of e-service technology. According to the literature review in the field of e-service technology and acceptance theories, this study identified the main factors influencing the acceptance of e-services, namely satisfaction, security and quality and then, dimensions of these factors were extracted from the previous studies. In order to categorise the dimensions, an exploratory survey was developed and conducted among the university students and then, the exploratory factor analysis was applied. Afterwards, a confirmatory survey was designed and conducted among the 427 Malaysians and tested in terms of validity (content and construct) and reliability and then used to evaluate the ETAM. Finally, the structural equation modelling was applied to validate the casual relations and to assess the goodness-of-fit. The results of this study revealed that quality, security and satisfaction significantly influenced the intention to use an e-service and consequently the acceptance of e-service technology. The ETAM can help evaluate and predict how users will respond to an e-service before starting the development of any e-service project. Additionally, ETAM can be used as a foundation for e-service providers to develop strategies to encourage people to use e-services and increase the usage and acceptance rate of e-services.     

XML-enabled workflow management for e-services across heterogeneous platforms

Advanced e-services require efficient, flexible, and easy-to-use workflow technology that integrates well with mainstream Internet technologies such as XML and Web servers. This paper discusses an XML-enabled architecture for distributed workflow management that is implemented in the latest version of our Mentor-lite prototype system. The key asset of this architecture is an XML mediator that handles the exchange of business and flow control data between workflow and business-object servers on the one hand and client activities on the other via XML messages over http. Our implementation of the mediator has made use of Oracle's XSQL servlet. The major benefit of the advocated architecture is that it provides seamless integration of client applications into e-service workflows with scalable efficiency and very little explicit coding, in contrast to an earlier, Java-based, version of our Mentor-lite prototype that required much more code and exhibited potential performance problems. Received: 30 October 2000 / Accepted: 19 December 2000 Published online: 27 April 2001     

A security policy framework for context-aware and user preferences in e-services

In today’s dynamic and distributed markets a large spectrum of services is delivered through information and communication technologies. Emerging markets of e-services lie at the intersection of non-traditional user behaviour, and cyber-partnerships of enterprises to deliver innovative services. Current approaches to manage and control security demonstrate lacks in terms of security policy matching and integration in heterogeneous e-service environments. In this paper, we introduce a framework to support role-based access control for distributed services focusing on the integration of customer preferences. The framework aims to collect and generate policy-based security measures in cross-organisational scenarios. In addition to catering to specifications of security and business policies, the ability to integrate contextual information and user preferences make the role-based framework flexible and express a variety of access policies that provide a just-in-time permission activation.     

Self-adaptable media service architecture for guaranteeing reliable multimedia services

The main objective of this paper is to design and develop a Self-Adaptable Media Service Architecture (SAMSA) for providing reliable dynamic composite multimedia service through policy-based actions. The multimedia services such as media retrieval, transcoding, scaling and display services are combined based on the preferences of the user to create a dynamic composite multimedia service called as Video-on-Demand service. Such distributed multimedia services deployed using Service Oriented Architecture (SOA) can be accessed in heterogeneous environments that are prone to changes during run-time. To provide reliable and adaptive multimedia services, a powerful self-adaptable architecture with dynamic compositions of multimedia services is necessary to adapt during run-time and react to the environment. The adaptability in this proposed architecture is achieved by enabling the service providers to Monitor, Analyze and Act on the defined policies that support customization of compositions of multimedia services and guarantee the Quality of Service (QoS) provisioning. The Media Service Monitor (MSM) observes the business and quality metrics associated with the multimedia services during run-time. The monitored results are analyzed by Monitored Results Analyzer (MRA) which identifies the type and location of the fault. The Adaptive Media Service Manager (AMSM) takes corrective actions based on the monitored results, through the policies defined as an extension of WS-Policy (Web Service—Policy framework). The effectiveness of the proposed Self-Adaptable Media Service Architecture (SAMSA) has been evaluated on Dynamic Composite Real-time Video-on-Demand Web Service (DCRVoDWS) for a maximum of 200 simultaneous client’s requests. The analysis of results shows that the proposed architecture provides better improvement on reliability, response time and user satisfaction.     

Ubiquitous collaborative iTrust service: Exploring proximity collective wisdom

Ubiquitous e-service is one of the most recent links in the chain of evolution that has characterized the different eras of the internetworking environment. In order to leap the trust barrier for the users to embrace these ubiquitous e-services, we present a collaborative iTrust e-service for exploring proximal collective wisdom in the ad-hoc ubiquitous environment. By highlighting the homophily of e-service participants, these isolated individuals can be treated as a group with proximity. Proximity thus enables ad-hoc e-service participants to contribute their strength for ubiquitous collective wisdom. Simulation outcomes for trust decision quality enhancement show significant improvement over traditional designs. The iTrust e-service makes it possible for users to collaborate with the nearby user groups for establishing a reliable and trustworthy interaction environment. It also facilitates and empowers the potential benefits of various ubiquitous e-service applications.

The design of a JADE-based autonomous workflow management system for collaborative SoC design

Given a fast changing electronics goods marketplace, designers of integrated circuits and components need to be more competitive, efficient, flexible, and use collaborative workflow to reduce time-to-market and a project’s life cycle. In recent years, agent-based workflow management systems (WfMS) have been widely used to monitor and control business design processes. In this paper, intelligent agents are applied to the collaborative system-on-chip (SoC) design environment. The proposed JADE-based autonomous workflow management system (JAWMS) uses a workflow coordination mechanism and an agent integration mechanism to enable the analysis, management and interaction of automated design processes. The workflow coordination mechanism uses five domain specific agents to perform the workflow enactment services and a generic agent to control the system flow logic. The system kernel of JAWMS follows the specifications of the workflow reference model provided by the workflow management coalition (WfMC). The agent integration mechanism supports an agent to interact with other JADE-based agent platforms and to coordinate and monitor workflow coordination messages. All agents are written in the Java language using the JADE platform and work together to perform flexible, adaptive and dynamic design tasks in an autonomous and collaborative way. JAWMS facilitates SoC design and team interaction in a collaborative but distributed product development environment.     

面向动态工作流的Web服务组合

利用动态工作流模型,将Web服务的组合过程与工作流的过程模型有机结合起来,从而建立面向动态工作流的复合服务。在复合服务的执行过程中,通过引入服务评价函数,并根据工作流过程模型中所定义的各项任务之间的业务逻辑与业务规则,最终实现工作流任务的动态绑定与执行。     

Workflow View Based E-Contracts in a Cross-Organizational E-Services Environment

In an e-service environment, workflow involves not only a single organization but also a number of business partners. Therefore, workflow inter-operability in such an environment is an important issue for enacting workflows. In this article, we introduce our approach of using workflow views as a fundamental support for E-service workflow inter-operability and for controlled visibility of (sub-)workflows by external parties. We discuss various aspects of a workflow view, and their semantics with example usage. Furthermore, we develop a contract model based on workflow views and demonstrate how management of e-contracts can be facilitated, with an Internet start-up E-service inter-organization workflow example.     

Dynamic checking of temporal constraints for concurrent workflows

At present, workflow management systems have not sufficiently dealt with the issues of time, involving time modelling at build-time and time management at run-time. They are lack of the ability to support the checking of temporal constraints at run-time. Although some approaches have been devised to tackle this problem, they are limited to a single workflow and use only static techniques to verify temporal constraints. In reality, there are multiple workflows executing concurrently in a workflow management system. There may well exist resource constraints between these concurrent workflows, which affect significantly the verification of temporal constraints at run-time. This paper proposes a novel approach for dynamic verification of temporal constraints for concurrent workflows. We first investigate resource constraints in workflow management systems, and then define concurrent workflow executions. Based on these definitions, we propose a verification method by analysing the temporal relationship and resource constraints between activities among concurrent workflows.