Anticipatory Planning using Execution Monitoring and a Constrained Planning Frontier

John M. D. HillLieutenant Colonel, U. S. Army

Assistant Professor, USMAPh.D. Candidate, TAMU

Dr. Udo W. Pooch Department of Computer Science

Texas A&M UniversityCollege Station, Texas

Dr. John R. “Buck” Surdu Major, U. S. Army

Senior Researcher, ITOCWest Point, New York

Agenda

• Introduction

• How we plan now and what we can do about it

• The Anticipatory Planning methodology

• A simple scenario

• Some ideas from the scenario

• A simple example of the methodology

• Status of the research

• Conclusion

How we plan now

• Traditional Military Decision Making Process (MDMP) focuses on developing a few friendly Courses of Action (COAs) against the “most-likely / most-dangerous” enemy COAs

• This results in a very detailed plan that considers only a few branches

• There is a well-known axiom in the military that “No plan survives the first shot” - this is another way of saying that a branch has occurred during execution which was not included in the plan

• When this happens, the commander and the staff immediately transition into reactive mode

• This is a bad thing!

What can we do?

• The Army needs a new way to perform planning while executing the operation so that it retains “option dominance”

• General (ret.) Wass de Czege has proposed an entirely new approach to military planning and execution called “Anticipatory Planning” that merges planning and execution

• As many branches as are reasonably possible are developed in the initial process, and as execution progresses the plan is continuously updated based on actual events

• Future branches that are known to be invalid are nominated for pruning and new branches are developed – well before they occur in execution

• Planning effort is expended on the most likely or most valuable branches

• Computational power, modern planning techniques, and rapid simulation can be applied to this problem to produce a powerful new planning and execution methodology and support system

PlanningExecutive

Proposed Methodology

WorldView

PlanDescription

WorldIntegrator

ExecutionMonitors

Planners

Data from thecurrent, real

operation(e.g., ABCS, GCCS, etc.)

Real informationplus “dead reckoned”

information

Plan Information Control Information

BranchesGenerator

BranchEvaluator

Major Components

• World View– Keeps track of the Actual State of the operation

• Plan Description– Represents the possible ways the operation can proceed– Nodes retain the Planned States; Branches have pre-conditions

• Planning Executive– Monitors use of system resources and determines the priority of planning– Controls the instantiation and activities of Execution Monitors and Planners– Constrains the Planning Space and the Planning Frontier

• Execution Monitor– Conducts forward simulation from the Actual State to produce an

Anticipated State at its monitored Node– Determines the significance of differences between the Anticipated State

and the Planned State at that Node, then makes a recommendation to the Planning Executive if re-planning is appropriate

• Planner– Invokes a Branches Generator to develop significant, representative

Branches– Invokes a Branch Evaluator to determine Viability and Likelihood Measures

Simple Scenario

• Blue Force mission:– Secure the Eastern Pass

– Don’t let the Red Force secure the Western Pass

• Red Force mission: secure the Western Pass• There is a time constraint

Plan One

• Red Force actions– Wait at the Eastern Pass

• Blue Force actions:– Wait at the Western Pass

• Plan Quality (Blue perspective)– Red does not secure Western Pass

– No Casualties

– FAILS to secure Eastern Pass

– Unrealistic Red option

Plan Description

Task Lists

Plan Two

• Red Force actions– Move south to the Western

Pass

• Blue Force actions:– Move south, engage Red,

move to the Eastern Pass

• Plan Quality (Blue perspective)– Red does not secure Western Pass

– Acceptable(?) casualties

– Secures the Eastern Pass

– More realistic Red option

Plan Description

Task Lists

Plan Three

• Red Force actions– Move north to the Western Pass

• Blue Force actions:– Move south, engage Red (oops!)– Move to the Eastern Pass

• Plan Quality (Blue perspective)– Red secures Western Pass

– No casualties

– Secures the Eastern Pass

– More intelligent Red option

Plan Description

Task Lists

Basic ideas

• Entities have attributes and can be assigned tasks• A Plan Description is composed of many actions

taken by the entities• The possibility of an entity choosing a different task

results in a Task Choice Point (TCP)• Emanating from the TCP, Branches represent the

flow of the battle for each choice• Typically, TCPs are binary (keep moving south, or

move north instead), but can have several branches• Some paths (chain of Branches) through the Plan

Description are better than others (in terms of how well they accomplish the mission)

Not-so-obvious ideas

• Outcomes can be deterministic or probabilistic• If you can’t plan all the way to completion, a local

measure of the viability of a Branch is a useful heuristic

• There are very many possible Task Change Points, but in reality there are usually only a few good ones

• When making a plan, remember that there is an adversary actively trying to make it fail

Simple Methodology Example

Node with an Execution Monitor

Actual State of the Operation

Node with a Planned State

Invalidation of Branches

Actual State of the Operation

Invalidated Branch

Node with a Planner

Re-Planning

Actual State of the Operation

Newly Generated

Still Invalidated

Newly Invalidated

Re-Validated

Nominated for pruning

Planning Frontier and Planning Space

Actual State of the Operation

PlanningSpace

PlanningFrontier

Status

• Simulations - built two special-purpose simulations– OpSim – Surdu, Haines, Pooch– HexGrid – Hill, Surdu, Pooch

• Planner– Tactical Event Resolver – Hill, Miller, Yen, Pooch

• Genetic Algorithm, Crisp rules

– Extending this planner using concepts from Gilmer, et al., on trajectory management to produce representative branches

• Execution Monitoring– Good results from Surdu’s Simulation during Operations

project (Operations Monitors)– Extending Operations Monitors to work with the Plan

Description

• Plan Description– Mostly developed, but still working issues of domain-

specificity and the “publish-and-subscribe” approach

Conclusion

• The Anticipatory Planning process accounts for the chaotic nature of warfare in which possibilities appear and disappear

• The purpose of this research is:– To maintain as many viable options in the plan as possible

– To focus planning effort where it will do the most good

– To help the commander and staff identify decisions that they { can | should | must } make NOW to ensure a desired option is available LATER

• The Anticipatory Planning process, aided by an automated support system built on the Anticipatory Planning methodology, will help U. S. forces achieve option dominance, providing a decisive advantage

• Come to WinterSim 2000 in December in Orlando to see our results!

Questions?

Planning Techniques

• Contingency Planning– Develop and consider every possible branch

– Not feasible for large planning spaces

• Probabilistic– Assign probabilities to branches and consider the most likely

– Still have to develop a lot of branches

– Sensitive to changes in the probabilities

• Interleaved Execution and Planning– Observe the results of execution, then plan based on the new

information

– Not a good idea to wait to find out what happens to start planning

• Reactive Planning– Develop reaction rules for specific conditions

– Difficult to build enough rules to cover all possible conditions