The image shows the relationships among the workflow services, including:

• Oracle BPEL Service Component (upper left side), which interfaces with the Task Service. The Task Service provides task persistence and exposes operations to update a task, complete a task, and escalate and reassign tasks. The Task Service interfaces with the Task Assignment Service, Evidence Store Service, User Metadata Service, Identity Service, and Task Metadata Service. The Task Assignment Service offers services to route, escalate, and reassign tasks. The Evidence Store Service captures digital signatures and checkpoints for digitally signed tasks. The User Metadata Service manages metadata related to workflow (user work queues, preferences, vacation, and delegation rules). The Identity Service provides user/group/role lookup, user authentication, authorization, and organization hierarchy. The Identity Service has the following possible user directory types: Oracle Internet Directory, JAZN XML, and LDAP, Custom. It also interfaces with the Policy Store, which contains information about application notes and permissions. The Task Metadata Service exposes operations to retrieve metadata information related to a task.

  The Task Assignment Service communicates with the Notification Service. The Notification Service sends notifications to users by e-mail, voice, IM, or SMS. The Task Assignment Service also communicates with the Task Metadata Service.

• Worklist application (upper right side) enables Web application to search for tasks, view tasks, and act on tasks. The Worklist application communicates with the Task Service and Task Query Service. The Task Query Service queries tasks for a user based on keyword, category, status, business process, attribute values, task history information, and so on. The Task Query Service communicates with the User Metadata Service and Identity Service (described above).

  The User Metadata Service communicates with the Runtime Config Services. The Runtime Config Services provide methods for managing metadata used in the task service runtime environment. The Runtime Config Services communicate with the Identity Service.