Human Workflow Services (HWS)

The Microsoft® BizTalk® Server 2004 engine enables you to connect applications to carry out a business process. Many processes—for example, handling a purchase order or responding to a request for proposal—require human intervention. Human-oriented business processes like these are commonly called "workflow." BizTalk Server 2004 can help to automate workflow, but more is required to enable people to interact with and control a workflow process.

Human Workflow Services (HWS) is a standard part of BizTalk Server 2004. HWS provides a workflow infrastructure built on the BizTalk Server 2004 engine. You access the HWS infrastructure by using Web services, so it can be used by any client application. The applications in Microsoft Office are among the most important clients that use HWS. Many information workers use Microsoft Word, Microsoft Outlook®, Microsoft Excel, and Microsoft Office InfoPath™, and so it makes sense to allow these common tools to be the environment from which people participate in workflows.

The following figure shows the basic model.

HWS workflow model

Activity flows are composed of one or more actions. An action represents a fundamental business process, or unit of workflow, that you cannot reduce to further sub-actions. Actions may contain zero or more tasks defining work.

Actions do not always send tasks. In dependent composition for example, actions send synchronization message and no tasks. A synchronization message is a message that an action sends or receives to or from another action when the action runs. For more information about dependent action composition, see Creating Dependent Actions. You assign tasks to the participants (called actors) in the workflow, which are external entities that either start an activity flow or participate in an ongoing activity flow. The actor who initiates the first action within an activity flow becomes the owner of the activity flow.

Note  HWS implements actions as BizTalk Orchestrations and implements tasks and responses as send or receive ports in a BizTalk Orchestration. Actors represent HWS users who participate in a HWS activity flow.

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