Pattern 26 (Selection Autonomy)
The ability for resources to select a work item for execution based on its characteristics and their own preferences.
Of the outstanding Pruning work items, the Head Gardener chooses the one for execution they feel they are best suited to.
The ability for a resource to select the work item that they will commence next is a key aspect of the "heads up" approach to process execution. It aims to empower resources and let them have the flexibility to prioritise and organise their own individual work sequence.
This pattern is a common feature provided by work list handlers in most PAIS. It typically manifests itself in one of two forms: either a resource is able to execute multiple work items simultaneously and thus can initiate additional work items of their choice at any time or they are limited to executing one work item at a time, in which case they can only commence a new work item when the previous one is complete although they can choose which work item they will commence next. Where a system implements "heads down" processing, it is common for the Selection Autonomy pattern to be disabled and for the system to determine which work item a resource will execute next.
There are no specifc context conditions associated with this pattern.
All of the workflow engines examined (except BPMN and UML 2.0 Ads which do not support any notion of worklist handler) provide support for this pattern.
One consideration with this pattern is whether resources are still offered complete flexibility to choose which work item they will undertake next when there are urgent work items allocated to them or whether the system can guide their choice or dictate that a specific work item will be undertaken next.
Where autonomy is offered to resources in terms of the work items that they choose to execute, it is typically not revoked even in the face of pressing work items. Staffware and WebSphere MQ provide a means of highlighting urgent work items but do not mandate that these should be executed. Other PAIS examined do not provide any facilities in this regard.
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.
|Staffware||9||+||Directly supported as the standard means for a resource to select the next work item|
|Websphere MQ Workflow||3.4||+||Resources can select the next item for execution from those on their work queue|
|FLOWer||3.0||+||Users can execute any work item at, ahead or behind the wavefront|
|COSA||4||+||Resources can select any of the work items on their queue to initiate next|
|iPlanet||3.1||+||Directly supported for offered work items|
|Oracle BPEL||10.1.2||+||Oracle BPEL PM supports this pattern directly. The user can select and act on any of the task displayed in his work list.|
|jBPM||3.1.4||+||jBPM supports this pattern.|
|OpenWFE||1.7.3||+||OpenWFE supports this pattern.|
|Enhydra Shark||2||+||Enhydra Shark supports this pattern.|
Summary of Evaluation