In general, a plan imposes a specific
strategy or behavior on a decision maker. A plan may simply specify a
sequence of actions to be taken; however, it could be more
complicated. If it is impossible to predict future states, then the
plan can specify actions as a function of state. In this case,
regardless of the future states, the appropriate action is determined.
Using terminology from other fields, this enables feedback or
reactive plans. It might even be the case that the state cannot
be measured. In this case, the appropriate action must be determined
from whatever information is available up to the current time. This
will generally be referred to as an information state, on which
the actions of a plan are conditioned.
Steven M LaValle