The BizTalk Server Business Rules Engine

Microsoft’s most widely used BRE today is provided as part of BizTalk Server. Despite how it’s packaged, this BRE can be used either with a BizTalk orchestration or with any .NET application. (And although using it requires licensing BizTalk Server, the product’s pricing is still competitive for a BRE.) To see how this technology might be used, think once again about the combined human and system workflow scenario shown earlier. In that example, BizTalk Server provided the system workflow and integration services that connected diverse applications, but the decision about whether to place high-value orders was made by people interacting via a Windows SharePoint Services workflow. It might be possible, however, to formalize the rules used to make this decision, then store them in the BizTalk Server BRE. Rather than relying on people, this business process could be implemented entirely in software. The figure below shows how this would look.

As the figure illustrates, the first three steps remain the same as in the previous scenarios. The decision to approve or reject a high-value order, however, is made by the BizTalk Server BRE (step 4) rather than by people. The BRE is invoked directly from the running orchestration, returning the result of its evaluation. As before, the order is then placed only if it was approved (step 5). If the rules underlying this decision can be expressed objectively and accurately, the benefit to the business process is clear: decision making will be faster and more consistent. It might also be more transparent, since the rules are now available in an external format—they’re no longer stored solely in people’s heads.
As this example shows, a BRE might be able to replace decisions made by people in a business process. It’s also possible for a process to use both decision-making approaches. In the example shown here, for instance, suppose that the decision criteria for some kinds of orders can’t be completely captured in formalized rules. It’s possible that along with the steps shown above, the process would also include a human workflow, perhaps implemented using Windows SharePoint Services. While a BRE might sometimes replace decisions made by people, the two can also be used together.