Linear planning is the process of finding a fixed sequence of operations or actions for a robot or software agent to perform in order to achieve a goal. For example, in order to make a mug of tea (goal) you have to (1) boil water, (2) put a teabag in a mug, (3) pour water into the mug, and finally (4) remove the teabag when fully brewed. It is in contrast to non-linear planning, which creates a partial order of actions; however, even a non-linear plan needs to be resolved to some single order when the agent needs to act.
Used in Chap. 15: page 224