Event-driven Dynamic Web Services Composition and Automation of Business Processes

Zakir Laliwala Dhirubhai Ambani-Institute of Information and Communication Technology

Gandhinagar, 382007, India zakir_laliwala@da-iict.org

Abstract B2B and long running B2C process are a complex

business process that contains set of services, state, transaction management, and involve notification of events occur during the execution of process. Business processes are driven by events and evaluating the business processes at regional or national scale reveals diversity in products, terminology and processes involved in carrying out a complete business activity. Because of dynamic nature, heterogeneity and lack of knowledge among business partner there is a need of mechanism to compose services dynamically according to events, and to provide interoperable integration for automation of business process. We proposed convergence of semantic web, web services and grid computing to achieve context and location based interoperable integration, event-driven dynamic composition, scalable architecture and middleware support for state, transaction, notification and life-cycle management of business process.

1. Background and Motivation More and more business organizations publish and

access their business using web technology. Interoperable B2B and B2C interactions have become a common requirement for enterprise applications. Any business process requires a set of services to fulfill its goal. If the goal is not satisfied by a single service then there is a need to combine the functionality of a set of services as composite services, to fulfill the requirements of any business process. Distributed heterogeneous services are to be integrated to complete the execution of a business process and interoperability among services is to be achieved when a process spans across the boundaries of multiple business organizations and domains with different vocabularies. Business processes are driven by events and each process should be capable of handling the dynamic nature of enterprise and business partners like change in the strategies, policies and exception handling. Heterogeneity, dynamic nature and lack of knowledge among business partners demand a scalable

architecture which can provide seamless interoperable integration, dynamic composition of distributed heterogeneous services, and automation of business processes with the management of state and transaction, notification of various events, and execution and monitoring of a process.

Web Services (WS) and Service-oriented architecture (SOA) are promising distributed computing paradigms and are well suited to solve the above-mentioned problems. The life cycle of WS based processes comprise of three phases: discovery, composition and execution. For each phase, the issues arise like, Standards and specifications are syntax oriented, lack of semantic support and not sufficient for certain kind of applications where composition, security, state and transaction management and middleware support are highly recommended.

For demonstrate we have taken real life example of Agricultural Info. System [5]. We have identified two use cases: Agricultural Marketing process [2][4][6] and Agricultural recommendation [3][1].

2. Contributions This research work is mainly focused on the

convergence of semantic web, WS and grid services to achieve interoperable integration, event-driven dynamic WS composition, execution with state and transaction management, notification and automation of a business process as shown in figure-1.

Figure 1: Convergence of SW, WS and GC WS provide loosely coupled integration of scattered

services, Semantic provide complete knowledge and

IEEE International Conference on Services Computing (SCC'06)0-7695-2670-5/06 $20.00 © 2006

vocabulary of domain and rules are designed to compose the WS dynamically according to event, and grid provides middleware support to achieve state, transaction, notification, execution monitoring & scalable enterprise architecture.

With this approach, we expect to achieve the following objectives: • Context and location aware interoperable

integration of distributed heterogeneous services. • Event-driven dynamic composition of WS with

negotiations, agreement, and state, transaction management.

• Provision of scalable architecture and middleware to provide support for flexible and scalable implementation of transparent business processes at enterprise level.

• Convergence of WS, Semantic Web and Grid services to provide effective implementation framework to achieve above mentions functionalities.

3. Our Proposal We propose the following semantic based service-oriented grid architecture. The proposal is mainly depend upon WS-* specifications, specifically WS-RF, WS-Notification, BPEL. Semantic web standards like RDF, OWL, and SWRL to achieve the compliance. Proposed architecture is shown in figure 2.

Figure 2: Proposed architecture 1.Information Services: Information services are

supporting as well as controlling components for execution of business processes. These services play the role of a mediator among the clients, business services, external information and knowledge providers. It is also responsible for composition of set of services according to the plan given by rules engine and by extracting domain knowledge and business knowledge from ontology. 2.Business Services: The services, which take part in business processes and require support for notification, state and transaction management are implemented as grid services and exposed as stateful resources. These services are part of grid environment to get benefits of grid like

security, execution and monitoring, resource sharing and scalability. 3.Grid Services: Various grid services like Composition Services, Event & Notification services [3], resource management services, job management services, are developed to manage the execution of process and control the behavior of grid. We utilize key functionalities of grid and inbuilt grid services like, service correlation, service isolation, self-discovery, virtualization, dynamic provisioning, resource pooling, persistent storage for lifecycle management, and execution and monitoring, which fulfill the functionalities of middleware and required for complete execution of a business process. 4.Ontology Server and 5.Rules Engine: Ontology provides support at two levels; one to provide the common vocabulary of a domain and another provide knowledge about various services involved in a business process. Rules enhance the functionality of semantic web and give behavioral knowledge, express constraints and define flow by reacting to the events.

Components 1,2,4,5,6 discussed in detail in our previous work [1-4][6] with related work and issues. Currently we are working on context and location based event-driven dynamic composition and workflow execution in grid environment. The future work includes development of tool for composition, verification and generation of composition schema based on formal model of event-driven composition.

4. References [1] Z. Laliwala, V. Sorathia and S. Chaudhary, "Semantics and Rule Based Event-driven Services-Oriented Agricultural Recommendation System", International Workshop on Distributed Event-Based Systems, 2006. [2] S. Chaudhary, Z. Laliwala and V. Sorathia, "Building Semantic Business Services", "The Semantic Web and its Applications", Eds. J. Cardoso and A. Sheth, Springer, 2006 [3] Z. Laliwala, V. Sorathia and S. Chaudhary, "Semantics based Event-driven Publish/Subscribe Service-Oriented Architecture", workshop on "Emerging Services delivery platforms and software models for Next Generation Network Services”, SOFTPLATFORM, 2006. [4] V. Sorathia, Z. Laliwala and S. Chaudhary, "Towards Agricultural Marketing Reforms: Web Services Orchestration Approach", Int. Con. on Services Computing(SCC), 2005. [5] S. Chaudhary, Z. Laliwala and V. Sorathia, "Architecture of Sensor Based Agricultural Information System for Effective Planning of Farm Activities", SCC, 2004. [6] Z. Laliwala, R. Khosla, P. Majumdar, S. Chaudhary, "Semantic and Rule Based Event-Driven Dynamic Web Services Composition for Automation of Business Processes", Third International Workshop on SDWP, 2006.

IEEE International Conference on Services Computing (SCC'06)0-7695-2670-5/06 $20.00 © 2006