Workflow task re-evaluation

1. An article comprising a non-transitory tangible machine-readable medium embodying instructions that when performed by one or more machines result in operations comprising:

identifying an occurrence of a workflow re-evaluation event during execution of tasks in a workflow under the control of a workflow management system, the workflow re-evaluation event being an exception execution state that does not comply with standard execution of the workflow, the workflow management system comprising a rules inference engine to control automation of the workflow;

suspending all active tasks in the workflow;

determining, for each task previously executed in the workflow, whether each such task needs to be executed again based on the identified occurrence of the workflow re-evaluation event, the determining comprising

associating, by the rules inference engine using data and control conditions associated with the workflow re-evaluation event, each task with one or more re-evaluation rules, each rule specifying a pre-condition to execute the corresponding task and a post-condition after the task is successfully executed; and

determining, using the rules inference engine, whether each task needs to be executed again based on the associated re-evaluation rules;

executing again those tasks in the workflow for which it was determined that the task needs to be executed again, the executing using contextual information from previously performed task;

executing suspended active tasks in the workflow for which it was determined that the task needs to be executed again;

skipping those tasks in the workflow that were previously executed and for which it was not determined that the task needs to be executed again, wherein at least one skipped task occurs subsequent to a task executed again in the workflow; and

canceling any suspended active task upon completion of the workflow.

2. An article as in claim 1 , wherein the workflow re-evaluation event is triggered when a business object for which the workflow has been defined is modified.

3. An article as in claim 2 , wherein the workflow re-evaluation event is triggered when one of a subset of entities within the business object is modified.

4. An article as in claim 1 , wherein the workflow re-evaluation event is assigned to the overall workflow.

5. An article as in claim 1 , wherein the workflow re-evaluation event is assigned to one or more of the tasks within the workflow.

6. A method for implementation by one or more data processor comprising:

identifying, by at least one data processor, an occurrence of a workflow re-evaluation event during execution of tasks in a workflow under the control of a workflow management system, the workflow re-evaluation event being an exception execution state that does not comply with standard execution of the workflow, the workflow management system comprising a rules inference engine to control automation of the workflow;

suspending all active tasks in the workflow;

determining, by at least one data processor for each task previously executed in the workflow, whether the task needs to be executed again based on the identified occurrence of the workflow re-evaluation event, the determining comprising

associating, by the rules inference engine using data and control conditions associated with the workflow re-evaluation event, each task with one or more re-evaluation rules, each rule specifying a pre-condition to execute the corresponding task and a post-condition after; the task is successfully executed; and

determining, using the rules inference engine, whether each task needs to be executed again based on the associated re-evaluation rules;

executing again, by at least one data processor, those tasks in the workflow for which it was determined that the task needs to be executed again, the executing using contextual information from previously performed tasks;

executing suspended active tasks in the workflow for which it was determined that the task needs to be executed again;

skipping, by at least one data processor, those tasks in the workflow that were previously executed and for which it was not determined that the corresponding task needs to be executed again, wherein at least one skipped task occurs subsequent to a task executed again in the workflow; and

canceling any suspended active tasks upon completion of the workflow.

7. A method as in claim 6 , wherein the workflow re-evaluation event is triggered when a business object for which the workflow has been defined is modified.

8. A method as in claim 7 , wherein the workflow re-evaluation event is triggered when one of a subset of entities within the business object is modified.

9. A method as in claim 6 , wherein the workflow re-evaluation event is assigned to the overall workflow.

10. A method as in claim 6 , wherein the workflow re-evaluation event is assigned to one or more of the tasks within the workflow.

11. A method as in claim 6 , further comprising:

suspending, by at least one data processor, all active tasks in the workflow;

executing, by at least one data processor, suspended tasks in the workflow for which it was determined that the task needs to be executed again; and

canceling, by at least one data processor, any suspended active tasks upon completion of the workflow.

12. An article comprising a non-transitory tangible machine-readable medium embodying instructions that when performed by one or more machines result in operations comprising:

identifying an occurrence of one of a plurality of workflow re-evaluation event during execution of tasks in a fragment of a workflow under the control of a workflow management system, the workflow re-evaluation event being an exception execution state that does not comply with standard execution of the workflow, the workflow management system comprising a rules inference engine to control automation of the workflow;

suspending all active tasks in the workflow;

determining, for each task previously executed in the workflow fragment using the rules inference engine and data and control conditions associated with the identified occurrence of the workflow re-evaluation event, whether each such task needs to be executed again based on the identified occurrence of the workflow re-evaluation event and based on whether each task has a corresponding re-evaluation rule specifying whether the task should be executed again during re-evaluation;

executing again those tasks in the workflow fragment (i) having re-evaluation rules specifying that the task should be executed again (ii) not having any corresponding re-evaluation rules;

executing suspended active tasks in the workflow for which it was determined that the task needs to be executed again;

skipping those tasks in the workflow fragment that were previously executed and for which it was not determined that the task needs to be executed again, wherein at least one task is skipped subsequent to a task being executed again; and

canceling any suspended active tasks upon completion of the workflow.

13. An article as in claim 12 , wherein the workflow re-evaluation event is triggered when a business object for which the workflow has been defined is modified.

14. An article as in claim 13 , wherein the workflow re-evaluation event is triggered when one of a subset of entities within the business object is modified.

15. An article as in claim 12 , wherein the workflow re-evaluation event is assigned to the overall workflow.

16. An article as in claim 12 , wherein the workflow re-evaluation event is assigned to one or more of the tasks within the workflow.