WSBP12. Addressable Software Component. Every end point service is identifiable using universal resource locator (URL). To know whether service is available, an invocation test to the service URL would provide the availability status of the service.

 

WSBP13. Web Services Needs. Web Services Technology is applied to meet certain business needs and objectives. The considering factors include reuse business components, integrate different IT platforms and disparate islands of technologies, direct business-to-business integration (B2Bi) between partners to facilitate information sharing. Understanding the basic needs would ascertain better drive of Web Services Technology to be applied appropriately.

 

WSBP14. Web Services Layering Architecture. The consideration for hierarchical abstraction for Web Services enables the decoupling relationship for services. This facilitates layered hierarchy representing ordered grouping of functionality abstraction for domain-specific application (upper layer), across domains application (middle layer), and deployment environment-specific application (lower layer).

 

The best practices for Web Services (i.e. the dos and donts of Web Services) will be based on the characteristics of Web Services listed. Understanding the best practices of Web Services helps us in addressing the SOA design and implementation challenges discussed earlier.

V. OUR METHODOLOGY

 

The analysis of the gaps of software methodology for Web Services (WS) and study of Web Services characteristics and best practices discussed earlier complement each other. This forms our basis of extending the existing agile software methodology with Web Services best practices (WSBP).

 

Our major effort is to go through every activities and tasks defined for each phase of the software lifecycle by analyzing how the Web Services best practices could fit in. The phases identified to be suitable for Web Service implementation lifecycle are: requirements, analysis, design, implementation, test, and deployment. The following sub-sections describe the consideration of WSBP discussed earlier.

 

A. Requirements Phase

The objective of this phase is to understand the business requirements and translating them into WS requirement in terms of the features, the functional and non-functional requirements, and the WS constraint. The WSBP13 provides a guideline for identifying Web Services, categorizing the needs into Web Services. The features required for the respective Web Services. Define use case models for the respective Web Services.

 

B. Analysis Phases

The objective of this phase is to refine the requirements further and translate the requirements into conceptual models. Architecting analysis is done to define high-level structure and identify the Web Services interfaces contracts. The WSBP1, WSBP2, WSBP5, WSBP6, WSBP10 and WSBP11 provide analysis guidelines for the following activities:

• Analyzing the granularity of Web Services interface contracts.
• Selecting technology platform for implementation framework.
• Defining Web Services candidate architecture. Identify architectural components to be exposed as WSs and specify major information exchanged with client.

 

C. Design Phase

The objective of this phase is to do detail design of Web Service. In this phase, the WS interface is refined further. The interaction of between the service and the client, e.g. asynchronous/synchronous or rpc/document is considered. The Web Services best practices for WSBP1, WSBP2, WSBP3, WSBP5, WSBP6, WSBP7 and WSBP14 are considered.

 

D. Implementation Phase

The objective of this phase is to do the actual coding of Web Services. The wrapping of components APIs to Web Services interface is done. The generations of WSDL and WS test client are produced. The WS will be deployed to the target application server. The WS best practices for WSBP1 to WSBP11 provide the guidelines for the implementation of Web Services.

 

E. Testing Phase

The objective of this phase is to conduct a complete test for Web Services including functional and non-functional requirements. The WS best practices for WSBP1 to WSBP11 provide guidelines for the testing of Web Services.