SOA Glossary

This glossary supports the following titles:

SOA: Principles of Service Design (ISBN: 01323 44823, Prentice Hall)

Service-Oriented Architecture: Concepts, Technology, and Design (ISBN: 0131858580, Prentice Hall)

Service-Oriented Architecture: A Field Guide to Integrating XML & Web Services (ISBN: 0131 428985, Prentice Hall)

For more information about this book series, visit: www.soabooks.com

schema standardization

When service capabilities are developed as part of different delivery projects, there is a natural tendency to customize contract schemas in support of project-specific business requirements and the initial composition the service capability is expected to participate in.

At a later point, when the same capability needs to be pulled into a new composition to fulfill new business requirements, the manner in which its contract represents input and output data may not be compatible with the schemas of other services it will be required to interact with.

For services with incompatible schemas to exchange data, a transformation technology is required. This generally introduces the need to design and develop a custom transformation layer consisting of logic that maps one schema to another. This logic is implemented as part of the service hosting environment and carries out its transformation every time data needs to be exchanged with affected service capabilities.

Data transformation layers are undesirable because they introduce extra development and design effort, and further impose a runtime processing layer that increases the overall performance overhead of service compositions.

The need for data transformation can be avoided by ensuring that service contracts are designed with compatible schemas from the beginning. This is achieved by applying design standards to each service contract. The result is referred to as schema standardization (also known as "data model standardization" and "data representation standardization").