Network and processing overhead associated with web services is a significant challenge to its performance. As a result, web service providers often announce a service level agreement. This ensures that consumers, who pay for the service, can get the service at a given quality level. In this paper, we study the competition between two providers offering functionally the same web services, whe...

In this paper the design and implementation of fault tolerable architecture for scientific workflow engines is presented. The engines are assumed to be implemented as composite web services. Current architectures for workflow engines do not make any considerations for substituting faulty web services with correct ones at run time. The difficulty is to rollback the execution state of the workflo...

By definition, web-services composition works on developing merely optimum coordination among a number of available web-services to provide a new composed web-service intended to satisfy some users requirements for which a single web service is not (good) enough. In this article, the formulation of the automatic web-services composition is proposed as several set-cover problems and an approxima...

Service-oriented architecture facilitates the running time of interactions by using business integration on the networks. Currently, web services are considered as the best option to provide Internet services. Due to an increasing number of Web users and the complexity of users’ queries, simple and atomic services are not able to meet the needs of users; and to provide complex services, it requ...

In general, Policy-based approaches play an important role in the management of web services, for instance, in the choice of semantic web service and quality of services (QoS) in particular. The present research work illustrates a procedure for the web service selection among functionality similar web services based on WS-Policy semantic matching. In this study, the procedure of WS-Policy publi...

Quality of service (QoS) is an important issue in the design and management of web service composition. QoS in web services consists of various non-functional factors, such as execution cost, execution time, availability, successful execution rate, and security. In recent years, the number of available web services has proliferated, and then offered the same services increasingly. The same web ...

In this paper the design and implementation of fault tolerable architecture for scientific workflow engines is presented. The engines are assumed to be implemented as composite web services. Current architectures for workflow engines do not make any considerations for substituting faulty web services with correct ones at run time. The difficulty is to rollback the execution state of the workflo...