Web Services Composition Methods and Techniques: A Review <s> YAN and XUE et al <s> Automatic composition of semantic Web services by requests is one of difficult problems in the field of Web services. In this paper we investigate Web services ontology and ant colony (AC) algorithm and propose a method of composition of semantic Web services (ACAC) that is based on ant colony algorithm. We generate a graph of input and output of semantic Web services, using this method, and then the composition of Web services is transformed into finding a satisfying path in the graph. So AC algorithm is used for efficient composition of Web services. Finally, we have tested ACAC with a test set and the results show that the algorithm can successfully compose the semantic Web services and is also able to ensure the quality and efficiency of composition. <s> BIB001 </s> Web Services Composition Methods and Techniques: A Review <s> YAN and XUE et al <s> By using semantic web service composition, individual web services can be combined to create complex, but easily reconfigurable systems. Such systems can play a vital role in today's changing economic conditions, as they allow business to quickly adapt to market changes. Taking into consideration that manual web service composition is both time-consuming and error prone, the proposed framework uses a semi-automatic approach. The composition is done in a fractal manner as existing web service chains can easily be incorporated in new web service chains. <s> BIB002 </s> Web Services Composition Methods and Techniques: A Review <s> YAN and XUE et al <s> This paper presents a semi-automatic Web service composition approach. This approach ranks all available candidate Web service operations based on semantic annotations and suggests service operations to a human designer during the process of Web service composition. The ranking scores are based on data mediation, functionality and formal service specifications. A formal graph model, an IODAG, is defined to formalize an input/output schema of a Web service operation. Three data mediation algorithms are developed to handle the data heterogeneities arising during Web service composition. The data mediation algorithms analyze the schemas of the inputs and outputs of service operations and consider the structures of the schemas. A typed representation for our data mediation approach, which formalizes the data mediation problem as a subtype-checking problem, is presented. An evaluation is performed to study the effectiveness of different data mediation and service suggestion algorithms used to assist designers composing Web services. <s> BIB003
• Semi-automatic/dynamic or static Composition Semi-automatic composition is the same automatic composition, but with the difference that according to the different conditions, it chooses different processes to accomplish goals. In this processes, the fixed processes and implementation of processes can be variability reflects the semi-automatic feature BIB001 . Wang and Guttula et al BIB003 presented a semi-automatic approach for web service composition that including both data mediation and service suggestion algorithms. This paper seeks to aid users trying to compose web services into a process by providing service suggestions. A graph IODAG (Input Output Directed Acyclic Graph) is defined to formalize an input/output schema of a Web service operation. Three data mediation algorithms leaf-based, structure-based and pathbased are developed to address data heterogeneities in process design. For adding semantic description into web services have used from Semantic Annotation for WSDL and XML Schema. This approach utilized various types of annotations and QoS. Finally they have developed a data mediation approach that tries to find automatically the optimal mappings between outputs and inputs. And finally came to the conclusion that path-based algorithm is best data mediation algorithm from other two algorithms. Adrian et al BIB002 present a semi-automatic approach. In their proposed approach the composition is done in a fractal manner using existing web service chains that can easily be incorporated in new web service chains. All web service chains in this framework are described using Web Service Business Process Execution Language (WS-BPEL) and be used as building blocks to create new service chains. All services are managed by intelligent agents. Besides the intelligent agents, other components of their framework are the annotated web services semantically. In this approach, existing web service chains are combined in a fractal like manner to easily create new and more complex web service chains. Talib et al  have suggested a method that semi-automatically generate static web service composition in BPEL4WS language. Their proposed system captures minimum necessary information from the user and stores them in a relational model and also captures the information required to develop the composition from the composition modeler and WSDL interfaces of the collaborating partners. Finally the transformation algorithm with all captured information is applied to map from relational to BPEL model.