In addition to the default pipelines, BizTalk Server includes two pipeline templates: a receive pipeline template and a send pipeline template. From a BizTalk project in Microsoft Visual Studio, you can add a pipeline template to your project by using the Add New Item command on the Project menu. Each template has an associated policy file, which determines the pipeline's stages and indicates which pipeline components are allowed in the pipeline. While you cannot reorder the stages in a policy file, you can use Pipeline Designer to reorder the components within a stage.
A policy file specifies:
The sequence of stages.
The number of components allowed per stage.
The execution mode of each stage.
The policy files for the pipeline templates are stored in <BizTalk Server installation directory>\Developer Tools\Pipeline Policy Files. Do not modify the policy files. To make changes to a pipeline, open the pipeline template and use Pipeline Designer to modify it. For more information about using Pipeline Designer, see Using Pipeline Designer.
The empty pipeline template files are stored in <BizTalk Server installation directory>\Developer Tools\BizTalkProjectItems, and are named BTSReceivePipeline.btp and BTSTransmitPipeline.btp. The file name extension .btp indicates that the file is a BizTalk Server pipeline and can be edited in Pipeline Designer.