Constraints for V&V of Agent Based Simulation: First Results A System-of-Systems Engineering Perspective Dr. Andreas Tolk Frank Batten College of Engineering and Technology Old Dominion University

V&V for Agents2 October 2, 2007Dr. Andreas Tolk Two Caveats Broader Perspectives on Agents and Application Domain –Real power (and money) lies in the C2 market: C2 M&S Services Support of Operations Analysis for the Warfighter in his HQ Decision Support –Agents are more than Human Behavior System perspective If it acts, it can be modeled as an agent Agents are not simple, but can be as complicated as traditional simulation systems

V&V for Agents3 October 2, 2007Dr. Andreas Tolk Value Chain for Net-Centric Operations Time Today Data Quality Information Quality Knowledge Quality Awareness Quality Systems, Messages Federations, Common Operational Picture Net-Centric Components, Common Operational Model Info-Centric GIG Services, SW Agents using M&S Services

V&V for Agents4 October 2, 2007Dr. Andreas Tolk Levels of Conceptual Interoperability Level 5 Dynamic Interoperability Level 4 Pragmatic Interoperability Level 3 Semantic Interoperability Level 2 Syntactic Interoperability Level 0 No Interoperability Level 1 Technical Interoperability Level 6 Conceptual Interoperability Increasing Capability for Interoperation Modeling / Abstraction Simulation / Implementation Network / Connectivity

V&V for Agents5 October 2, 2007Dr. Andreas Tolk Ontological View Concept SymbolReferent Semiotic triangle of Ogden Ogden, C.K., and Richards, I.A. The Meaning of Meaning: A Study of the Influence of Language upon Thought and of the Science of Symbolism, University of Cambridge, 1923

V&V for Agents6 October 2, 2007Dr. Andreas Tolk Traditional View: System Analysis and Design Coherent Model (Repository) Data Modeling (Item) Process Modeling (Function) Behavior Modeling (System)

V&V for Agents7 October 2, 2007Dr. Andreas Tolk System Architecture Perspective Requirements Functional Architecture Physical Architecture Operational Architecture Interfaces & Items

V&V for Agents8 October 2, 2007Dr. Andreas Tolk System-of-Systems Perspective Requirements Functional Architecture Physical Architecture Operational Architecture Interfaces & Items Requirements Functional Architecture Physical Architecture Operational Architecture Interfaces & Items Requirements Functional Architecture Physical Architecture Operational Architecture Interfaces & Items Requirements Functional Architecture Physical Architecture Operational Architecture Interfaces & Items Scope Resolution Structure

V&V for Agents9 October 2, 2007Dr. Andreas Tolk Agents as Systems Agents are Systems of System –Agents in the Simulated Environment –Agents working with other Agents –Agents working against other Agents –Agents building ad-hoc Federations The Promise of System Engineering –Reduce complexity by decomposing system into manageable sub-parts –Integration brings system back together

V&V for Agents10 October 2, 2007Dr. Andreas Tolk What is an Agent Agent –a computer program (or, more usually, a part of a program) –which represents some real world actor (e.g. a person, an organisation, a nation) –with inputs (perception) –With outputs (actions) –With rules (what to do) Goal Environment Representations Communication Perception Communication Action

V&V for Agents11 October 2, 2007Dr. Andreas Tolk A General Model for an Agent Blueprint for Decomposition: Taxonomy for agent architectures Source: Moya L, Tolk A (2007) Towards a Taxonomy of Agents and Multi-Agent Systems, SpringSim Vol I, pp

V&V for Agents12 October 2, 2007Dr. Andreas Tolk Structural Variances External Measures of Merits Agents’ Goals and Objectives Scope Resolution Structure

V&V for Agents13 October 2, 2007Dr. Andreas Tolk Environments Accessible Deterministic Episodic Static Discrete Non-Accessible Stochastic Sequential Dynamic Continuous

V&V for Agents14 October 2, 2007Dr. Andreas Tolk Situated environment – “world information;” objects agents can affect and be affected by Population –characteristic descriptions of the MAS Agent characteristics – decision, action, perception, goals, etc. (as depicted on Slide 8) High Level Taxonomy Source: Moya L, Tolk A (2007) Towards a Taxonomy of Agents and Multi-Agent Systems, SpringSim Vol I, pp

V&V for Agents15 October 2, 2007Dr. Andreas Tolk Systems Everywhere An agent is a system –Data Model (Input, Output, Controls) –Process Model (Functions) –Behavior Model (Mode and State Changes) The environment is a system –Interaction in the environment –Interaction with the environment Agent Populations are Systems-of-Systems –Communications –Exchangeable information, Language Cascading V&V necessary -V&V for the agent components -V&V for the agent - V&V for the agent in the environment - V&V for the agent within the population - V&V for the agent within the population in the environment -V&V for the agent population in the environment

V&V for Agents16 October 2, 2007Dr. Andreas Tolk Multi-Agents Agent Communicating Sphere of influence Environment

V&V for Agents17 October 2, 2007Dr. Andreas Tolk

V&V for Agents18 October 2, 2007Dr. Andreas Tolk Resulting V&V Challenges Can we V&V perception, communication, and action for potential (re)use Can we V&V reasoning & decision making, reactivity, beliefs, memory, and goals Can we V&V the agent in different environments –Accessible, deterministic, episodic, static, discrete –Non-accessible, stochastic, sequential, dynamic, continuous Can we V&V agents for use in different agent populations Can we V&V emerging behavior in agent populations Classical V&V methods fall short regarding these requirements. A Multilayered Cascading Framework is Necessary!

V&V for Agents19 October 2, 2007Dr. Andreas Tolk Advertisement Agent-Directed Simulation Symposium (ADS'08) Part of the 2008 Spring Simulation Multiconference (SpringSim'08) Sponsored by: The Society for Modeling and Simulation International (SCS) in collaboration with ACM/SIGSIM Dates: April 14-17, 2008 Crown Plaza Ottawa, Ottawa, Canada