Serial Workflow variation::Runtime pattern

Service Consumer and Service Providers are linked via a Workflow Manager and Connectors. The Workflow Manager node is also linked with a Rules Directory and a Staff Worklist Adapter node.
Design Last Updated: 10-20-2004
(Click a node to get a detailed explanation.)

The Runtime pattern shown above represents a basic topology for the implementation of the Application Integration::Serial Workflow variation. It can be further enhanced by clustering the key nodes to improve the availability characteristics.

This basic topology leverages the following nodes with the associated responsibilities:

• Workflow manager node
  This node contains the workflow execution engine that coordinates the process flow across systems and people. It provides the capability for model-driven business process automation and enables tracking by leveraging the process execution rules stored in the associated database. These processes can span multiple applications and people across organizational boundaries within an enterprise.
  The node maintains state and tracks sequencing through the process flow. In doing so, it often leverages the associated database to store intermediate results. It is also responsible for invoking target applications as necessary through the associated connectors.
  When a particular task requires human interaction, this node creates a work item and identifies a particular person or a department responsible for executing that task and adds the work item to its work list.
• Staff worklist adapter node
  A specialized adapter is responsible for presenting the work items to be executed by a particular person or a department. It is the primary interface through which people interact within the end-to-end workflow.
• Connector nodes
  A connector node is used to provide connectivity between:
  • The application server/services node and the process manager
    This allows a source application to communicate with a process manager.
    Process managers usually support multiple connector types.
  • The process manager and an application server/services node
    This allows a process manager to communicate with a target application.
    Process managers usually offer multiple connector types.
• Rules Directory node
  This node provides a persistent data storage and retrieval service in support of the execution of the process flow. It holds the process execution rules.

In this second section we specialize the Workflow variation pattern for the SOA environment using the SOA profile. The SOA profile terminology is indicated using the [SOA] qualifier.

[SOA]Serial Workflow variation

Service Consumers and Providers are linked via an Enterprise Service Bus and a Business Service Choreography node.
Design Last Updated: 10-20-2004
(Click a node to get a detailed explanation.)

This [SOA] PI pattern will be redrawn following the next series of SOA redbooks. It will abstract the picture, removing user, internet and application representations.

The diagram illustrates how the WS-I sample business scenario is applied to this Runtime pattern. This sample business scenario shows a supply chain management process. The scenario is developed by the Web Services Interoperability Organization and is designed to test compliance with the WS-I Basic Profile.

The key benefits of using Business Service Choreography are:

• Flexibility: achieved by externalization of process logic for the individual application.
• Human interaction: facilitating various staff functions such as approval, investigation, and claim.
• Reusability of the software components or services in the process, resulting in cost savings.
• The construction of processes from services with explicit interfaces enables the easy substitution of one service interface with another.