Usage Scenario: Single or Multiagent Plan Coordination Service

Author(s): Jeffrey Cox and Edmund Durfee, University of Michigan

URL(s) or other references:

Domain: Planning, Multiagent Coordination, Synergy


This is a service provided to coordinate the independently generated plans of one or more agents to resolve conflicts and exploit unexpected cooperative opportunities. Our service supports both a partial-order and a hierarchical plan representation of agent activity.


At its core, the plan coordination service works to resolve conflicts and exploit unexpected cooperative opportunities between subplans of a single agent, identifying individual plan steps between the plans that either conflict (meaning that they must be synchronized in order to ensure correct execution) or are redundant, meaning the steps can be combined into a single step,  reducing the agent's execution cost.

The service supports more sophisticated problems in which each plan belongs to a separate agent (human, robot, computer program, organization, etc.) and the goal is to prevent interference and exploit common actions between the agents to improve plan execution. In addition, the service also supports an expanded plan representation in which agent plans are represented hierarchically (both in decomposition and option selection).  The service can reason about interactions between agent plans at various levels of abstraction, exploiting the representation to more quickly arrive at coordinated solutions.

Stakeholders & Interests

Stakeholders can include an individual wishing to integrate existing solutions to subproblems when solving a larger problem or different organizations wishing to coordinate their behaviors given their existing planning solutions.

Actors & Goals

Modification History

Use Case: Plan Coordination


  1. Input: Independenty generated plans from a single or multiple agents, sharing a common plan format.
  2. Input: Sets of goals for each participating agent.
  3. Input: [Optional - Search guidance, or solution preferences]
  4. Output: Modified, coordinated plans in the shared format.



Automated plan coordination and plan merging. 


Environments in which separate plans to achieve specific goals have already been formulated, and that are now to be executed in a shared context (thus introducing the possibility of interaction between plan executors).  Examples might be:


Inputs and Output formats agreed on by participating agents.


Simple case is a single coordination episode, in which agents submit their plans, the coordination system searches for and identifies required/optional modifications, and returns modifications to the agents who then execute their plans. A more sophisticated usage scenario is an iterative/sequential one, in which agents iteratively submit plans, receive coordination feedback, and resubmit plans to further improve their coordinated behavior.


Fits well within a larger system for partitioning a planning problem into subproblems, planning for each problem separately, and then integrating subplans together.

Ontologies Needed

Initial plans to be coordinated, plan representation and solution criteria.

Reasoning Techniques Required

Search, action refinement, synchronization, constraint satisfaction, unification, hierarchical planning

Open Issues or Questions

None noted.