Biztalk Pipeline Question:

When you create a new application, the default pipelines are created and deployed by default and appear in the Microsoft.BizTalk.DefaultPipelines assembly in the References folder for every BizTalk project. The default pipelines cannot be modified in Pipeline Designer. These pipelines can be selected when configuring a send port or receive location in BizTalk Explorer.

Pipelines and pipeline components present out of the box can do most of the tasks for you. But sometime specific message processing or messaging requirements encourage developers to develop custom pipeline components. You can create three types of pipeline components: general, assembling, and disassembling. Each of the three types can additionally implement probing functionality. Each type of pipeline component has an associated interface that must be implemented for the component to be plugged into the BizTalk Messaging Engine; the pipeline interfaces that distinguish the types of components are IComponent, IAssemblerComponent, and IDisassemblerComponent. A custom pipeline component is just a plain .NET class that implements several BizTalk interfaces.