The point of a pull system is to use a kanban board to limit work-in-progress by pulling from the previous phase of your value stream when necessary.

Yet many would acknowledge that the theory has great value in illuminating such aspects of our moral experience as reaching decisions when we feel the pull of conflicting obligations.

The paper studies the integration between digital service provider and network service provider on the value chain in the environment of 3G, analyzes separately the push SC and the pull SC.