Tight Bounds for HTN Planning with Task Insertion (Extended Abstract)

Abstract

Hierarchical Task Network (HTN) planning with task insertion (TIHTN planning) is a variant of HTN planning. In HTN planning, the only means to alter task networks is to decompose compound tasks. In TIHTN planning, tasks may also be inserted directly. In this paper we provide tight complexity bounds for TIHTN planning along two axis: whether variables are allowed and whether methods must be totally ordered.

Hierarchical planning and reasoning about partially ordered plans—From theory to practice

“…Another major contribution of mine is thus the formalization of a hierarchical problem class where such action insertions are permitted. The resulting framework is called HTN planning with task insertion — or (TIHTN) planning (Geier and Bercher 2011; Alford, Bercher, and Aha 2015b).…”

“…Based on this observation, we conducted a comprehensive complexity analysis of all the special cases for HTN planning outlined before (Alford, Bercher, and Aha 2015b).…”