Simkit Analysis Workbench for Rapid Construction of Modeling and Simulation Components

UNCLASSIFIED

Simkit Analysis Workbench for Rapid Construction of Modeling

and Simulation Components

Arnold Buss, Don Brutzman, Curt Blais, Rick Goldberg, John McGregor, John

Ruck.

Naval Postgraduate School

Monterey, CA

24 June 2004 UNCLASSIFIED 2

WCM Project Overview

NSSSimkit

CombatXXI

SimkitAnalytical

Workbench

JFEOModeling

ImproveStrike

Module

AT/FP: Anti-Terrorism / Force Protection

CombatXXI: Next-generation Army/Marine analytical model

JFEO: Joint Forcible Entry Options

MAS: Multi-Agent Simulation

NSS: Naval Simulation System

+ AT/FP

XMSF / X3D viz / Web Services N81 Analyses SAVAGE and MAS

SAVAGE: Scenario Authoring and Visualization for Advanced Graphical Environments

Simkit: Discrete Event Simulation (DES) Application Programmers Interface (API)

X3D: Extensible 3D Graphics

XMSF: Extensible Modeling and Simulation Framework

Analytical Modeling Framework


Overview

• Introduction

• Event Graph Methodology

• Simkit Java Implementation

• XML Schema for Event Graph Representation

• Viskit, Visual Tool for Event Graph Construction

• Demonstration


Introduction

• Barriers to use of simulation models Simulation = “Big and Costly” Time to develop model Lack of rigorous methodology Lack of rapid-development tools


Introduction (cont)

• Breaking the Barriers Event Graph Methodology Simkit Programming API Viskit Graphical Tool XML Schema for Component

Representations

• Tools to Build Tools to build Models


Event Graph Methodology

• “Pure” Discrete Event Simulation (DES)

• Four Elements to DES Model Parameters State Variables Events (State Transition Functions) Scheduling Relationships Between Events


Event Graph Methodology (cont)

A B(i)

A Bt (i)


Simple Event Graph

Run Arrival

{N = 0} {N = N + 1}

tA

tA


More Complicated Event Graph

StartService

EndService

{Q=Q+1} {Q=Q-1,S=S-1}

{S=S+1}

(S > 0)

(Q > 0)

tS

Run Arrival

{Q = 0, S = k}

tAtA


Event Graph Components

• Based on “Listener” Pattern

• Loosely Coupled Simulation Components

• Listener Event Graph Objects (LEGO)


SimEventListener Pattern

• SimEvent Source dispatches its SimEvent to registered SimEvent Listeners

• All SimEvents (except “Run”) are “heard” by Listener

• Used for assembling models from components

SimEventSource

SimEventListener


Example: Multiple Server Queue

ArrivalStart

ServiceEnd

Service

{Q=Q+1} {Q=Q-1, S=S-1} {S=S+1}

(S > 0)

(Q > 0)

tS

Run

{Q=0, S=k}

Run Arrival

{N = 0} {N = N + 1}

tA

tA

Arrival Process

Server


PropertyChangeSource

PropertyChangeListener

Property Change Listener Pattern

• PropertyChangeEvents fired at every state transition

• Listener may register for specific or all PropertyChange Events

• Used for statistics, graphing, etc.


Property Change Listener Example

ArrivalStart

ServiceEnd

Service

{Q=Q+1}{Q=Q-1, S=S-1}

{S=S+1}

(S > 0)

(Q > 0)

tS

Run

{Q=0, S=k}

Simple StatsTimeVarying

(Q)

Simple StatsTimeVarying

(S)


Simkit

• Java API for creating Event Graph models

• Open Source• Effective for teaching DES• Used in more than 30 NPS Masters

Theses• Implements Listener Event Graph

Object pattern


Simkit

• Based on solid Event Graph methodology

• Enables reasonably rapid construction of DES models

• NPS OR/MV students able to implement models in matter of a few months

• Enabler for implementing new features in DES models


Recent NPS Theses using Simkit

• REMUS vehicle for mine detection (Allen, 2004)

• Repair and Sparing of Jet Engines (Schoch, 2003)

• Operational Availability of MMA (Margolis, 2003)

• Submarine Mine avoidance (Nawara, 2003)• Dynamic Allocation of Fires and Sensors

(Havens, 2002)


Viskit Motivation

• Simkit requires Java programming

• Need for non-programmer use

• Need for rapid development tool

• Organize reusable components

• Repository of existing models and components for reuse


XML for Event Graph Components

• Data-centric representation of Event Graph Components

• XML is standard, open data format

• Language and Implementation independent

• Enabler for web services


Code Generator

• Generates Simkit Java code from XML document

• SimEntity XML document -> SimEntityBase subclass

• Assembly XML document -> instances of SimEntities and Listeners


Viskit Event Graph Editor

• Even more rapid development of Event Graph Components

• Exposes Event Graph structure better than code

• Modeler draws Event Graph and fills in information

• Open Source


Viskit Event Graph Editor

Scheduling/Canceling Edge

Drawing Canvas

State Variables

Simulation Parameters

Create New Event

Self-Scheduling Edge


Server Component in Viskit


Viskit Assembly Editor

• “Assembly” consists of Instances of SimEntities and

PropertyChangeListeners Listening connections

arrival server

numInQueueStat

numAvailableServerStat


Viskit Assembly Editor

Event Graph Components

PropertyChangeListeners

New Instance Wizard

Listener Connection Toolbar

Assembly Canvas

Execution Controls



Problem

• Investigate control systems for the delivery of indirect fire

• System includes: Targets Sensors Shooters Logistics delivery Logistics depot Central controller


Quinone

• Developed by MAJ Alistair Dickie, Australian Army

• Model created in ~ 2 weeks (in “spare” time!) using Simkit

• Analyzed at 8th Project Albert Workshop

• Demonstration


Quinone - Results

• Supplier assignment most critical• Valuing a pairing of supplier/shooter based on ammo

holding of shooter much more important than valuation based on distance

• Assignment of shooters to contacts Very sensitive to

Contact Age Distance to contact

Not sensitive to Ammo holding Contact importance

Assignment interactions• A 15 day old model can give you results (now 18 days

old)


Summary

• Rapid DES modeling is possible

• Event Graph Methodology robust

• Simkit implementation mature, stable

• Viskit application accelerates development time

• Basic features and design of Viskit complete


Ongoing Work and Improvements

• Improve “user-friendliness” of Viskit

• Add Experimental Design and execution features

• Execution on computer clusters

• Documentation, Help and Tutorial

• Incorporate features based on user feedback and testing


POC

Arnie Buss

(831) 656-3259

[email protected]

Simkit may be obtained from:

http://diana.gl.nps.navy.mil/Simkit/


Questions

Documents

Simkit Analysis Workbench for Rapid Construction of Modeling and Simulation Components