Plansuch

Plansuch is a term used in discussions of automated planning and heuristic search to denote the process of finding a viable plan by exploring a space of possible actions and subplans. The word combines the German roots plan and such (search), reflecting its linguistic origins while the concept has been adopted in English-language AI discussions as well.

Overview and concept: Plansuch treats planning as a search problem in which nodes represent partial or full plans and edges correspond to plan refinements or the application of actions. It emphasizes the integration of planning and search rather than a strict separation between generating a plan and executing it. Plansuch approaches aim to identify sequences of actions that satisfy constraints such as goals, resources, and temporal orderings.

Approaches and techniques: Methods associated with plansuch include plan-space search, partial-order planning, and heuristic-guided exploration over plan representations. Heuristics estimate the remaining cost or feasibility of partial plans, guiding the search toward promising regions of the plan space. Some implementations combine domain models, goal reasoning, and execution monitoring to adjust plans in light of feedback from real-world execution.

Applications: Plansuch concepts are applied in robotics for task execution under uncertainty, in logistics for scheduling and routing, and in interactive software agents and game AI for adaptive planning. The term is often used as a broad label for families of techniques that blend planning with search, rather than a single algorithm.

History and terminology: The term emerged in planning literature in the late 20th and early 21st centuries and varies by author. In some contexts, more specific terms such as plan-space planning or plan-search are used interchangeably or to highlight particular methodological emphases. Plansuch remains a general descriptor for integrated planning-and-search methodologies.