Event-based scheduling method and system for workflow activities

• US 20020170035A1
• Filed: 02/28/2001
• Published: 11/14/2002
• Est. Priority Date: 02/28/2001
• Status: Active Grant

• Current Assignee: Valtrus Innovations Limited (f/k/a Dolya Holdco 9 Limited) (Key Patent Innovations Limited)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Casati, Fabio, Shan, Ming-Chien
• Granted Patent: US 7,240,324 B2
• Time in Patent Office: Days
• US Class Current: 717/127
• CPC Class Codes: G06F 8/10 Requirements analysis; Specification techniques
• CPC Class Codes: G06F 9/542 Event management; Broadcasting; Multicasting; Notifications

Abstract

An event-based scheduling method and system for providing automatic activity synchronization and automatic data exchange between workflows and between workflows and other applications. An automatic synchronization mechanism is provided for enabling workflows to interact with other workflows or other applications to automatically synchronize activity execution. An automatic data exchange mechanism is provided for enabling workflows to exchange data with other workflows or other applications. An event processing pre-compilation architecture receives a workflow definition having at least one event node and responsive thereto generates a workflow definition without event nodes at compile time. Each event node is replaced with a translated workflow node that conforms to the syntax supported by the underlying workflow engine. The translated workflow node is also assigned to an application that can implement the desired event node semantics. An event processing run-time architecture invokes the application assigned to the translated node when the translated node is encountered. The application employs a publication and subscription tool for automatically performing activity synchronization and/or data exchange at run time.

Claims

1. A method for event-based synchronization in a workflow having at least one event node comprising the steps of:

a workflow having a plurality of work nodes;

encountering an event node that specifies an event;

suspending execution of the workflow and waiting for the occurrence of the event; and

proceeding to a next work node only when the event occurs.

2. The method of claim 1 wherein the event node includes a request node that specifies a point where execution is suspended until a specified event is delivered.

3. The method of claim 1 wherein the event node includes a send node that specifies a point where events are produced.

4. The method of claim 1 further comprising the step of:

providing automatic cooperation between the current workflow and an external process by employing a publish and subscribe event notification, whereby a workflow designer does not need to specify a specific process instance involved in the cooperation.

5. The method of claim 1 further comprising the step of:

communicating data between the current workflow and another process.

6. The method of claim 1 further comprising the step of:

when the event node is a request node, receiving information regarding the current workflow to a receiver of the request.

7. The method of claim 1 further comprising the step of:

when the event node is a send node, sending information regarding a sender of the event.

8. The method of claim 1 wherein the event is one of an event triggered by a process, a workflow, an application, or a human trigger.

9. The method of claim 8 further wherein the workflow is one of a workflow in an enterprise that is common to the current workflow, a workflow in an enterprise that is different from the current workflow, an application in an enterprise that is common to the current workflow, an application in an enterprise that is different from the current workflow.

19. The system of claim 1 further comprising:

at least one event node;

wherein the event node specifies filtering rules of events of interest based on the values of event parameters.

10. A system for processing workflow definitions having at least one event node with desired event node semantics comprising the steps of:

a workflow engine for processing workflow definitions and for supporting a predetermined workflow syntax;

an event node handler for receiving a workflow definition having at least one event node and responsive thereto for generating at compile time a workflow definition with translated event nodes

wherein the event node handler includes an event node replacement unit for replacing each event node with a translated workflow node that conforms to the predetermined workflow syntax supported by the workflow engine; and

a node application assignment unit for assigning an application to each translated workflow node that can implement the desired event node semantics

11. The system of claim 10 further comprising:

a run-time architecture for invoking at run time at least one application assigned to a translated node.

12. The system of claim 10 further comprising:

a publication and subscription tool for use by an application to publish events and subscribe to events.

13. The system of claim 12 wherein the system enables workflows to interact with other workflows or other applications to automatically synchronize activity execution.

14. The system of claim 12 wherein the system enables workflows to interact with other workflows or other applications to automatically data exchange.

15. The system of claim 10 wherein the event node is one of a send node and a receive node.

16. The system of claim 11 wherein the application is one of a send application and a receive application.

18. The system of claim 17 comprising:

an event dispatcher for dispatching events by utilizing a publish-subscribe model;

wherein processes notify events to all interested processes and receive events of interest from other processes through the event dispatcher.

17. An workflow management system comprising:

a first process;

a second process for cooperating with the first process;

an automatic cooperation facility to automatically synchronize execution of activities in the first process and the second process, for exchanging data between the first process and the second process, for notifying state changes of the first process and the second process, for notifying that certain milestones have been reached in process execution, and for requesting the activation of a remote process from the first process and the second process.

20. A method for processing event nodes in a workflow definition comprising the steps of:

a) during compile time, translating the workflow definition with event nodes into a revised workflow definition with translated workflow nodes;

during run-time

b) when a translated request node is encountered, invoking a request application;

c) the request application subscribing with an event broker for an event of interest by specfying required parameters;

d) when an application publishes an event that matches the required parameters of the event of interest, the event broker delivering the event to the request application;

e) when a send node is encountered, invoking a send application; and

f) the send application publishing an event with an event broker.

21. The method of claim 20 further comprising after step (d) the step of:

returning a work item to a workflow that had a request node.

22. The method of claim 20 further comprising the step of:

g) the send application returning to a workflow that had the send node a success code when successful and a failure code when not successful.

23. A method for processing event nodes comprising:

an event broker for providing event publication and subscription services;

a send application for processing send nodes and for publishing at least one event with the on the event broker;

a request application for processing request nodes and for subscribing to at least one event on the event broker; and

a workflow engine for invoking the send application when processing a send node and for invoking the request application when processing a request node.