Cognition · Software component
Graph Search Planner
Software componentCognitionCognition & MemoryVariation point (abstract)arc:GraphSearchPlanner
A task planner that finds a lowest-cost action or path sequence by systematically searching a weighted state-space graph from the current state to a goal state.
Responsibility. Systematically searches a state-space graph for a lowest-cost path to the goal.
Also known as: Pathfinding planner, Search-based planner, Informed search planner
Variant of Task Planner abstract
Variants
| Variant | When to choose |
|---|---|
| Bounded-Suboptimal Search Planner | Choose for real-time games, robots under time pressure and interactive systems where responsiveness outweighs optimality and cost may exceed optimal by up to factor w. |
| Memory-Bounded Search Planner | Choose when memory is scarcer than time: embedded systems, mobile devices with strict memory budgets, or search spaces far exceeding available RAM. |
| Optimal Heuristic Search Planner | Choose when the state space admits informative admissible heuristics, optimal solutions matter more than computational efficiency, the branching factor is manageable and transitions are deterministic (e.g., route planning on a known warehouse floor plan). |
| Uniform-Cost Search Planner | Choose when many destinations share one origin (20+), when the graph is tiny (~50 nodes), when repeated queries on a static graph amortise preprocessing, or when no meaningful goal-distance heuristic exists. |
Relationships
invokes dependency
- Heuristic Estimator abstract Ch5.6
is invoked by dependency
reads dependency
produces lifecycle
- Execution Plan abstract Ch5.6
Design guidance
- SHOULD be chosen for deterministic transitions with well-defined costs and a clear goal direction; stochastic or adversarial domains favour Monte Carlo Tree Search.
- MUST treat its search results as stale when edge costs or obstacles change during execution and hand over to a replanner.
- SHOULD select the search variant from time constraints, solution-quality tolerance, memory budget and number of destinations.
Quantitative guidance
As stated by the sources; verify before use.
- Warehouse robot: optimal 47 m path required expanding 380 of 50,000 nodes in 185 ms, exceeding a 100 ms path-update deadline (Ch5.6).
Classification
- Patterns
- A* searchBest-first searchOpen/closed list searchf(n) = g(n) + h(n) evaluation
- Quality attributes
- Functional suitability: correctness and validity (ISO/IEC 25010 | NIST AI RMF: valid)Performance efficiency (ISO/IEC 25010)
- Risks mitigated
- Exhaustive exploration of irrelevant paths
Sources
- Ch5.5: T. Nguyen, "Monte Carlo Tree Search Fundamentals," in Mastering Agentic AI Systems: Guide for the NVIDIA NCP-AAI Exam, 1st ed. 2026, ch. 5.5. ISBN: 9798244538229.
- Ch5.6: T. Nguyen, "A* Search and Replaning," in Mastering Agentic AI Systems: Guide for the NVIDIA NCP-AAI Exam, 1st ed. 2026, ch. 5.6. ISBN: 9798244538229.