Zaiwen Feng

QoS-aware and multi-granularity service composition

Composition of Web services can be very complex, and usually involves multiple atomic services and varieties of message exchange patterns. Worst still, with the increasing amount of available services with varying granularity and quality, selecting the best combination of services becomes very challenging. This paper addresses the issues on multi-granularity service composition with awareness of the service quality. In particular, we consider how a new service composition plan is produced, while preserving its original observable behaviors of a service that are shown to the service user, by substituting the service with another service or a set of services of finer or coarser grain. The new plan aims to have services of better quality (if the corresponding underlying services are available). To achieve this, we firstly define a behavioral signature model to capture observable behaviors of services. We then present that two service composition plans are choreography equivalent if they comply with the same behavioral signature model. We then propose a behavioral extracting algorithm to obtain the behavioral signature model from a service composition plan. We also present a method to determine choreography equivalence. Finally we briefly describe our prototype implementation that captures all these proposed algorithms.

Towards individualized requirements specification evolution for networked software based on aspect

Networked software is a kind of Internet-based online complex softwaresystem produced through interaction and cooperation between networksand users who act as both consumer and producer of the system composed ofweb services. To meet a mass of individualized requirements, specifications forcommon requirements of the domain need to modify and evolve. Aiming at theconcern, we propose a 3-step process of requirements evolution modeling ofnetworked software. Focusing on the first step, the paper analyzes inducementsfor individualized requirements evolution, proposes a meta-model to describe theevolutionary requirements specification of networked software based on aspects,and presents a case study to demonstrate the usage of our approach. Finally aprocess for implementing the individualized requirements evolution is proposed.So it is helpful to guide the modeling for evolutionary requirements specificationsand implement individualized requirements from common specifications.

Taxonomy for Evolution of Service-Based System

With the rapid development of service computing related technology, the number of application of service based system (SBS) in enterprise is increasing rapidly. Research on evolution of SBS is becoming more and more important. In this paper, we propose a taxonomy framework for evolution of SBS, which is illustrated from five perspectives: (a) motivations of SBS evolutionary changes (why), (b) stakeholders of SBS evolutionary changes (who), (c) locations of SBS evolutionary changes happening (where), (d) times of SBS evolutionary changes happening (when), (e) support mechanisms in the process of SBS evolutionary changes (how). Furthermore, propagation of evolutionary changes of SBS is analyzed in the paper.

A Service Registry Meta-model Framework for Interoperability

currently there exist many kinds of semantic Web Service models on the internet. They are heterogeneous so that it is hard to understand and interoperate each other. In this paper, we study several mainstream semantic Web Service models, and extract meta-models for each from the perspective of semantic Web Service discovery. Based on this, we propose the universal meta-model for semantic Web Service registration within the background of meta-model framework for interoperability (MFI, ISO/IEC19763). Some cases are studied and infrastructure supporting our work is demonstrated. The work in the paper may be regarded as an extension to UDDI on service semantics facet, and has been proposed to ISO as ISO/IEC 19763 Part 7.

Towards a Taxonomy Framework of Evolution for SOA Solution: From a Practical Point of View

Presently, the research on evolution of SOA solution is becoming more and more important in industry. It is necessary to extract a taxonomy framework for evolution of SOA solution because by using it, evolution of SOA-based systems can be analyzed and compared comprehensively and objectively. In this paper, a taxonomy framework for evolution of SOA solution is proposed that is illustrated from four perspectives: (a) motivations for evolutionary changes (why), (b) locations where evolutionary changes happen (where), (c) times when evolutionary changes happen (when), and (d) support mechanisms in the process of evolutionary changes (how). Furthermore, the taxonomy framework is applied on analyzing a SOA-based configurable system for urban logistics delivery management, as an application of taxonomy framework.

Efficient and Exact Query of Large Process Model Repositories in Cloud Workflow Systems

As cloud computing platforms are widely accepted by more and more enterprises and individuals, the underlying cloud workflow systems accumulate large numbers of business process models. Retrieving and recommending the most similar process models according to the tenants requirements become extremely important, for it is not only beneficial to promote the reuse of the existing model assets, but also helpful to reduce the error rate of the modeling process. Since the scales of cloud workflow repositories become bigger and bigger, developing efficient and exact query approaches is urgent. To this end, an improved two-stage exact query approach based on graph structure is proposed. In the filtering stage, the composite task index, which consists of the label, join-attribute and split-attribute of a task, is adopted to acquire candidate models, which can greatly reduce the number of process models needed to be tested by a time-consuming verification algorithm. In the verification stage, a novel subgraph isomorphism test based on task code is proposed to refine the candidate model set. Experiments are conducted on six synthetic model sets and two real model sets. The results demonstrate that the presented approach can significantly improve the query efficiency and reduce the query response time.

A Unified RGPS-Based Approach Supporting Service-Oriented Process Customization

Software as a Service (SaaS) aims to provide utility-oriented software delivery and provisioning. While software being published as reusable Web APIs, users can quickly compose multiple services into a new value-added process: a mashup. However, various users may have different requirements, thus preferring to compose the same set of services in different ways. Therefore, there is a need to provide a unified way for users to configure and compose services. RGPS (Role, Goal, Process, and Service) is an ongoing ISO-standard meta-model framework for describing service usage requirements. This chapter presents an approach of leveraging RGPS to help users configure a personalized service-based mashup. Based on users’ requirements, a hierarchical goal tree is generated for users to further refine their business goals. According to mappings between goals and variation points in business process templates, a personalized business process will be created. One task in a business process may be realized by an external service. Corresponding visualization tools are introduced to assist users. This chapter also describes a case study of customizing a mashup over an established service supermarket.

A collaborative food safety service agent architecture with alerts and trust

With the recent advances in Internet and mobile technologies, there are increasing demands for ubiquitous access to food safety information for service integration and gathering first hand information. However, due to disparate food trading information among different food suppliers throughout the food supply chain such as food importers, food wholesalers, food retailers, it is still difficult for citizens to use them effectively during their marketplace shopping. To overcome this problem, we propose a Collaborative Food Safety Agent System (CFSAS) based on a scalable, flexible, and intelligent Multi-Agent Information System (MAIS) architecture for proactive aids and trust-based decision support on food purchasing to citizens. We formulate our MAIS architecture for CFSAS further with agent clusters based on a case study of the Center for Food Safety (CFS) in Hong Kong. Agent clusters may comprise several types of agents to achieve the goals involved in the major processes of a food safety mechanism. We show how agents help citizens better plan, understand, and specify their preferences collaboratively with the CFSAS. We further illustrate how this can be implemented with Web service technologies to integrate disparate food information resources along the food supply chain.

A Requirements-Driven and Aspect-Oriented Approach for Evolution of Web Services Composition

Service-oriented software development emerges to be popular with the development of Internet and Web service.Web service offers agility and adaptability to rapid changes of users’ requirements. Goal models depict users’ desires in terms of goals, namely, why-to-do; BPEL provides means to describe web service composition using WS-BPEL2.0, namely, how-to-do. However, there exists a gap between changes of individualized requirements and web service composition in the meet-in-the-middle pattern. So, in the paper we proposed an aspect-oriented approach to support web service composition evolution triggered by requirements evolution. The approach elevates the abstraction level of evolution modeling for web service composition, namely, from business process level to strategic goal level. The result is to make business level person capable of taking part in evolution modeling at requirements phase.

Dynamic semantics of OWL-S in CSP-OZ

Service oriented computing (SOC) is a promising paradigm to reuse and integrate existing services to develop applications across organizations for fulfilling value-added purpose. Networked softwork is a kind of classic application of SOC. It is of complicated and evolving topology and behaviours. The requirement engineering is posed by the serious challenge towards the highly volatile business requirements in the service-oriented development setting. Toward the challenge, we have proposed requirement meta modelling frame, named O-RGPS, which is the methodology combining ontology techniques, domain modelling, and requirement engineering. We choose process part of OWL-S as process description language during domain modelling and business process design. It is important to ensure the correctness of business process before service deployment. To achieve it, formalization of the chosen language is needed to do first. In this paper, we make two contributions: on the one hand, the process part of OWL-S is defined in an abstract and succinct manner; on the other hand, the language is formalized in CSP-OZ.