Multi-Method Simulation Modeling using AnyLogic Andrei Borshchev, CEO XJ Technologies INFORMS Roundtable Fall Meeting November 3-4, 2007 Seattle © 2007 XJ Technologies www.anylogic.com This presentation… •…is NOT about what you do with the model after it is completed and can be treated as a black box The Optimizer The Model © 2007 XJ Technologies www.xjtek.com 2 This presentation… The Optimizer The Model • …is about HOW you develop simulation models, choose abstraction level and methodology © 2007 XJ Technologies www.xjtek.com 3 Modeling The Real World ? The Problem The Solution © 2007 XJ Technologies www.xjtek.com 4 Modeling The Model The Optimized Model The World of Models The Real World The Problem The Solution © 2007 XJ Technologies www.xjtek.com 5 [Dynamic] Simulation Modeling The Simulation Model • Executable – A set of rules telling how to obtain the next state of the system from the current state • Gives the trajectory of the system in time •Dynamic – Causal and time dependencies – Time-related constraints • Complex – No analytical solution The System © 2007 XJ Technologies www.xjtek.com 6 Methods Process-centric System Dynamics (Discrete Event) Jay Forrester, 1950s Geoffrey Gordon, 1960s The System 1990s Agent Based © 2007 XJ Technologies www.xjtek.com 7 Methods Process-centric System Dynamics (Discrete Event) Jay Forrester, 1950s Geoffrey Gordon, 1960s The System System-level 1990s Agent Based Individual-centric © 2007 XJ Technologies www.xjtek.com 8 Methods Process-centric System Dynamics (Discrete Event) Jay Forrester, 1950s Geoffrey Gordon, 1960s The System 1990s Agent Based Continuous, Discrete, Aggregated Disaggregated © 2007 XJ Technologies www.xjtek.com 9 Abstraction levels. Modeler communities High Abstraction Less Details High aggregation, quantities, global feedback dynamics, … Macro Level SD Strategic Level AB International System Dynamics Conference DE Winter Simulation Conference, INFORMS, IIE Low Abstraction [No business-oriented conference] More Details Micro Level Operational Level Individual objects, exact sizes, distances, velocities, times © 2007 XJ Technologies www.xjtek.com 10 Tools AB SD VenSim PowerSim RePast iThink Swarm ASCAPE NetLogo … DE Arena ED Extend FlexSim PROMODEL Automod SimProcess Simul8 Quest emPlant Witness … © 2007 XJ Technologies www.xjtek.com 11 AnyLogic AB SD DE © 2007 XJ Technologies www.xjtek.com 12 AnyLogic OO Language Java/Eclipse platform Windows, Mac OS, Linux Interactive Animation SD AB Statistics Data presentation OptQuest included + Teamwork support GIS support Open at Java level Export models as applets DE … 1. You can easily vary the level of abstraction and viewpoint until it perfectly fits the problem 2. You can mix different methods in one model © 2007 XJ Technologies www.xjtek.com 13 “No Workarounds!” • Do not fight the modeling language and the tool! • If you feel the SD abstraction level (stocks, flows, feedback dynamics) is enough for the problem, use aggregated view • If the system can be naturally represented as a process (sequence of operations, entities, resources) – use DE • If you are more comfortable with specifying individual behavior of objects (people, vehicles, companies, assets, projects, etc.) – use AB © 2007 XJ Technologies www.xjtek.com 14 Why this is important: cell telecom example Market IT Infrastructure A cell telecom provider runs GPRS in test mode with few customers © 2007 XJ Technologies www.xjtek.com 15 Why this is important: cell telecom example FREE! Market IT Infrastructure Before launching GRPS officially the company declares it is free – as a marketing action © 2007 XJ Technologies www.xjtek.com 16 Why this is important: cell telecom example FREE! Market IT Infrastructure A lot of users start using GPRS because it is free – much more than IT infrastructure can handle © 2007 XJ Technologies www.xjtek.com 17 Why this is important: cell telecom example Market IT Infrastructure Users frustrated with poor QoS leave the company forever © 2007 XJ Technologies www.xjtek.com 18 Why this is important: cell telecom example Model of A combined Market Market + Supply Chain FREE! Model can predict such effects Market IT Infrastructure Model of Supply Chain © 2007 XJ Technologies www.xjtek.com 19 A quick tool demo => © 2007 XJ Technologies www.xjtek.com 20.