Service Component Architecture (SCA) is one of the most popular standards, dating from 2005. It defines the architectural components of an SOA platform in a technical manner. It is standardized by the OASIS, mainly in collaboration with IBM, Oracle, and TIBCO.

It provides a model to compose applications that follow the SOA principles:

In a nutshell, SCA has the following key elements:

• Assembly model:
  • Defines the structure of composite applications by having series of artifacts defined by elements contained in XML files
• Composite:
  • Is a basic artifact, which is the unit of deployment for SCA
  • Contains one or more components
  • Eventually, it holds remotely accessible services
• Component:
  • Contains business functions
  • Functions are exposed as services, which can either be used internally or by other components made available through entry points
  • When a component depends on services provided by other components, these dependencies are called References
• Services:
  • Remotely accessible web services, primarily based on XML
• Implementations:
  • These are present in components
  • They are configurable by the component statically or dynamically
  • SCA provides the implementation and binding specifications
• Policy Framework:
  • Specifies how to add constraints, security, transactions, QoS, and messaging policies
• Enterprise service bus (ESB):
  • SCA specifies inclusion and usage of the ESB
• Service Data Objects (SDO):
  • Service Data Objects to access the data sources

With further sections, we will see the software implementation perspectives of the SOA platform and finally look at some indicative sample code with .NET Core.