Pattern 18 (Early Distribution)
The ability to advertise and potentially distribute a work items to resources ahead of the moment at which it is actually enabled.
The Captain BA12 London - Bangkok flight work item is offered to potential Chief Pilots at least two weeks ahead of the time that it will commence.
Early Distribution provides a means of notifying resources of upcoming work items ahead of the time at which they need to be (or can be) executed. This is useful where resources are able to provide some form of forward commitment (or booking) indicating they they will execute and complete a work item at some future time. It also provides a means of optimising the throughput of a case by ensuring that minimal time is spent waiting for resource allocation during case execution.
Where a process contains a task that is identified as being subject to Early Distribution, the existence of any work items corresponding to the task can be advertised to resources as soon as an instance of a process is initiated. Depending on the nature of the specific PAIS, these advertisements may simply be an advance notification of (as in some case handling systems) they may constitute as actual offer or allocation of a work item. However in both cases, such notifications do not imply that the work item is ready for execution and it is only when the process advances to the task to which the work item corresponds, that the work item can actually be commenced.
There are no specific context conditions associated with this pattern.
None of the offerings examined directly support this pattern, suggesting that the focus of production PAIS tends to be on the management and completion of current work rather than on planning the optimal execution strategy for future work items. FLOWer (a case handling system) provides the ability for a resource to view future work items and potentially commence work on them even though they are not the next items in the process sequence. The case handling paradigm offers a different approach to work allocation. It is not discussed in detail here and interested readers are referred to van der Aaslt et al's article [AWG05] for further information.
An offering achieves full support if it satisfies the description for the pattern.
To achieve a + rating (direct support) or a +/- rating (partial support) the product should satisfy the corresponding evaluation criterion of the pattern. Otherwise a - rating (no support) is assigned.
|Websphere MQ Workflow||3.4||-||Not supported|
|FLOWer||3.0||+||Resources are able to view and execute tasks ahead of the wavefront|
|Oracle BPEL||10.1.2||-||Oracle BPEL PM offers no support for this pattern|
|jBPM||3.1.4||-||jBPM does not support early distribution.|
|OpenWFE||1.7.3||-||OpenWFE does not support this pattern.|
|Enhydra Shark||2||-||Enhydra Shark does not support early distribution.|
Summary of Evaluation