A pipeline is a set of pipe runs, or line segments that share a set of properties representing a connected section of a pipe. When you retrieve a Smart P&ID drawing on which a pipeline is published, the pipeline is created in the line list authoring environment. In addition, a pipeline can be created manually from a collection of line list records or automatically because of a roll up.
The pipelines can contain any number of line list records, though a line list record can be associated with only one pipeline.