Web Services Composition Methods and Techniques: A Review <s> Automatic/Dynamic Composition <s> A huge amount of web services are deployed on the Web, nowadays. These services can be used to fulfill online requests. Requests are getting more and more complicated over time. So, there exists a lot of frequent request that cannot be fulfilled using just one web service. For using web services, composing individual services to create the added-value composite web service to fulfill the user request is necessary in most cases. Web services can be composed manually but it is a too tedious and time consuming task. The ability of automatic web service composition to create a new composite web service is one of the key enabling features for the future for the semantic web. There are some successful methods for automatic web service composition, but the lack of standard, open, and lightweight test environment makes the comparison and evaluation of these composition methods impossible. In this paper we propose an architecture for a light weight and scalable testbed to execute, test and evaluate automatic web service composition algorithms. The architecture provides mandatory components for implementing and evaluation of automatic web service composition algorithms. Also, this architecture provides some extension mechanisms to extend its default functionalities. We have also given reference implementations for web service matchmaking and composition. Also, some scenarios for testing and evaluating the testbed are given. We have found that the performance of the composition method will dramatically decrease as the number of web services increases. <s> BIB001 </s> Web Services Composition Methods and Techniques: A Review <s> Automatic/Dynamic Composition <s> Agent-oriented analysis and design is a prosperous approach to model and build software systems. On the other hand, semantic web services are software components that have been emerging to enable dynamic service discovery, composition, invocation, and provide services, which can be considered as the main function of an agent. Semantic web service composition is a feature that improves the flexibility of the system. In this paper we propose a multi-agent system for web service composition. We modeled it by MaSE (Multi-agent System Engineering) methodology, which is a top-down approach. Also an implementation of our system is illustrated for semantic search engines. The case study shows that our system is feasible and effective for composition of semantic web services in a distributed network. <s> BIB002 </s> Web Services Composition Methods and Techniques: A Review <s> Automatic/Dynamic Composition <s> Web services technologies are becoming a de facto standard to integrate distributed applications and systems using XML-based standards. Developing applications that support web services interfaces will not be enough to provide complete and coordinated business processes. Thus, we need a new approach to compose these web services together in order to form web services orchestration and processes definition There are two methods for web service composition. One is static composition and the other is dynamic composition. Automated web service composition is a very challenging task. This paper proposes a new dynamic web services composition algorithm to solve the composition issues related to data distribution, reliability, availability and QoS. <s> BIB003 </s> Web Services Composition Methods and Techniques: A Review <s> Automatic/Dynamic Composition <s> With the increasing number of web services available on the internet, the need for automated web services composition is becoming more and more important. A number of approaches have been proposed to tackle this problem. In this paper, we firstly summarize existing web service composition approaches, and then we present a service classification management mechanism to organize web services more efficiently and accurately. Finally, we design an automated web services composition system, which consists of two main parts: service management subsystem and service provision subsystem. The service management part is based on the service classification management mechanism, and service provision part is to meet the need of users' request by AI Planning. <s> BIB004 </s> Web Services Composition Methods and Techniques: A Review <s> Automatic/Dynamic Composition <s> Service composition is an important mean for integrating the individual Web services to create new value added systems that satisfy complex requirements. However, it is challenging to guarantee the reliability of service composition in a distributed, dynamic and complex environment. This paper proposes an approach to constructing the reliable service composition. The underlying formalism is Petri net, which provides means to observe behaviors of basic component, and to describe their interrelationship. The transaction attributes, reliability and failure processing mechanisms are articulated. The composition mechanism systematically integrates these schemas into a transaction mapping model. Based on this, a reliable composition strategy and its enforcement algorithm are proposed, which can verify the behaviors of service composition at design time or after runtime to repair design errors. The operational semantics and related theories of Petri nets help prove the effectiveness of the proposed method. Finally, we use a simplified Export Service system to demonstrate the feasiability of the method. <s> BIB005
The dynamic composition creates process model and selects atomic services automatically and requires the requester to specify several constraints including the dependency of atomic, the user's preference and so on [2] Since, Manual web service composition is time-consuming and hard task, the automatic or computer aided (semiautomatic) composition of web services is a recent trend. Also the need for automatic composition of web services with the increasing number of web services available on the internet is become more and more important BIB004 . The automation [2] means that either the method can generate the process model automatically or the method can locate the correct services if an abstract process model. For automatic web service composition, Semantic web is proposed. Ontology is used to give well-defined meaning to the semantic web BIB001 . Semantic web service composition BIB002 is a feature that improves the flexibility of the system. An automatic web service composer should compose ''right" services in a composition according to the user's specification. The ability of automatic composition of web service for creating a new composite web service is one of the key features for the future of the semantic web. Furthermore, composite web services BIB005 are dynamic that their components can be automatically selected at run-time based on specific requests. Mostly automatic composition techniques are either interface based or functionality based. In interface based composition, inputs and outputs through interfaces of users obtains composite web services and after composition the desired results are achieved. The drawback of it this is that functionality is not guaranteed, whereas in functionality based composition, user provides the formula that explains logic with interface information. Most of these methods are based on Artificial Intelligence (AI) planning BIB003 . There are many problems in artificial intelligence that are very similar to the automatic web service composition: artificial intelligence planning, automatic software generation, automatic workflow generation, logical deduction, etc BIB001 . In automatic composition of web service agents are used to select a web service that may be composed of multiple web services, but from user's viewpoint, it is considered as a atomic service  . There are some successful methods for automatic web service composition that the following mentioned: