4 Layers in an SOA
There are 4 layers in an SOA:
- Business Processes
- Business Services
- Integration Services
- Enterprise Resources
Enterprise Resources
- existing applications
- COTS systems (consumer, off the shelf)
- Object Oriented systems
- Legacy systems (eg CRM + ERP)
- Data at this layer resides in existing applications and databases
- Operations have a specific, structured interface
- Operations return structured responses
- These applications provide transactions
- single, logical units of work in the enterprise operational systems
- Responsible for reading, writing and modifying data
Integration Services
- Provide access and interfaces to existing applications
- Expose existing applications as services
- Involve translation from whats actually available in the application to whats desired as an enterprise service
Business Services
- Provide high-level functionality
- Provide an interface abstraction from the implementations in layers below
- Provide virtual implementation of related business processes that can be re-used across multiple systems
- Break the direct dependance between business processes and the underlying applications
- provide business processes (eg customerProfiling) through the logical grouping of related operations (eg search customer by email)
Business Processes
- Series of operations that are executed in an ordered sequence
- Described in a business process model (BPM)
- Executed by a business process management system (BPMS)
- Included in orchestration in terms of
- Execution
- Sequencing
- Selection
- Provide long-running sets of activities
- Operate on business documents
- Composed of business activities
Sources: https://en.wikipedia.org/wiki/Service-oriented_architecture
