Part
III
Heuristics and
Control Strategies
Although planning systems have become much more efficient over the years, they
still suffer from combinatorial complexity. As described in Chapter 3 on the com-
plexity of planning, even relatively restricted planning domains can be intractable
in the worst case.
The four chapters in this part of the book are devoted to several approaches
for improving the efficiency of planning. To provide a foundation for presenting
these approaches, we now describe an abstract common framework for the planning
procedures presented earlier in the book.
Nearly all of the planning procedures in Parts I and II of this book can be viewed
as instances of the Abstract-search procedure shown in Figure III.1. The objective
of Abstract-search ...