The Bazaar pipeline plugin helps you organize your changes into
sections called "pipes". Pipelines can help you:

* focus on each set of changes as a coherent piece, without being
  distracted by other sets of changes.
* respect diff size limits when submitting changes
* avoid reviewer fatigue when submitting changes for code review
* maintain a set of patches against an upstream branch

WWW: http://wiki.bazaar.canonical.com/BzrPipeline