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METAHEURISTICS IN SCIENCE AND INDUSTRY: NEW DEVELOPMENTS . Fred Glover OptTek Systems, Inc. Boulder, Colorado Andreas Reinholz University of Dortmund Dortmund, Germany. Metaheuristics International Conference June 25-29, 2007. OptTek Customized Simulation Optimization Applications.
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METAHEURISTICSIN SCIENCE AND INDUSTRY: NEW DEVELOPMENTS Fred Glover OptTek Systems, Inc.Boulder, Colorado Andreas Reinholz University of Dortmund Dortmund, Germany Metaheuristics International Conference June 25-29, 2007
OptTek Customized Simulation Optimization Applications • Portfolio Management • Supply Chain Applications • Strategic and Operational Planning • Financial Planning • Manufacturing Process Flow • Resource-Constrained Scheduling • Network Planning • Routing & Distribution • Data Mining • Biotechnology • Health Care
Standard Optimization SoftwareOptQuest® • AnyLogic (a product of XJ Technologies Company) • Arena (a product of Rockwell Software/Systems Modeling Corp.) • Crystal Ball (a product of Decisioneering, Inc.) • CSIM (a product of Mesquite Software) • Enterprise Dynamics (a product of Incontrol) • FlexSim (a product of FlexSim Software Products, Inc.) • Micro Saint (a product of Micro Analysis and Design, Inc.) • OQNLP (a joint product developed with Optimal Methods, Inc.) • Parallel OptQuest® (enabled by Paradise®, a product of Scientific Computing) • Premium Solver Platform (a product of Frontline Systems) • Promodel/Innovate (products of Promodel Corporation) • Quest (a product of Delmia Corp.) • SimFlex (a product of Flextronics) • SIMPROCESS (a product of CACI) • SIMUL8 (a product of SIMUL8 Corporation) • TERAS (a product of Halliburton’s Landmark Graphics) • VIEO 1000 (a product of VIEO Corporation)
The Optimization Challenge • Function to be Optimized • Highly Nonlinear • Nondifferentiable • Discrete or Continuous or Mixed • Function Evaluations • Complex • Extremely Computation Intensive • One second to One Day per Evaluation!
OptQuest® Components • Evolutionary Scatter Search • Advanced Tabu Search • Linear & Mixed Integer Programming • Pattern Classification & Curve Fitting • Neural Networks • Support Vector Machines & Trees • SAT Data Mining
OptQuest® vs. RiskOptimizer Efficiency is Critical!
Problem • Given a set of opportunities and limited resources… • …determine the best set of projects that maximizes performance
Portfolio Selection Problem • Constraints: • Budget • Resource Availability • Scheduling and Sequencing of Projects • Project Dependencies, etc. • Objectives: • Maximize Net Present Value (NPV) • Maximize Internal Rate of Return (IRR) • Maximize Business-Case Value (BCV)
Application Example • 5 Projects: • Tight Gas Play Scenario (TGP) • Oil – Water Flood Prospect (OWF) • Dependent Layer Gas Play Scenario (DL) • Oil – Offshore Prospect (OOP) • Oil – Horizontal Well Prospect (OHW) • Ten year models that incorporate multiple types of uncertainty • Evaluation Time: 1s / Scenario
Base Case Base Case TGP = 0.4, OWF = 0.4, DL = 0.8, OHW = 1.0 E(NPV) = 37,393s =9,501 Determine project participation levels [0,1] that Maximize E(NPV) Keep s < 10,000 M$ (Risk Control) All projects start in year 1
Deferment Case Base Case Deferment Case TGP = 0.4, OWF = 0.4, DL = 0.8, OHW = 1.0 E(NPV) = 37,393s =9,501 TGP1 = 0.6, DL1=0.4, OHW3=0.2 E(NPV) = 47,455s =9,513 10th Pc.=36,096 Determine project participation levels [0,1] AND starting times for each project that Maximize E(NPV) Keep s < 10,000 M$ (Risk Control) Projects may start in year 1, 2, or 3
Probability of Success Case Base Case Deferment Case Probability of Success Case TGP = 0.4, OWF = 0.4, DL = 0.8, OHW = 1.0 E(NPV) = 37,393s =9,501 TGP1 = 0.6, DL1=0.4, OHW3=0.2 E(NPV) = 47,455s =9,513 10th Pc.=36,096 TGP1 = 1.0, OWF1=1.0, DL1=1.0, OHW3=0.2 E(NPV) = 83,972s =18,522 P(NPV > 47,455) =0.99 10th Pc.=43,359 Determine project participation levels AND starting times for each project that Maximize P(NPV > 47,455 M$) Keep 10th Percentile of NPV > 36,096 M$ Projects may start in year 1, 2, or 3
Extensions… • Cash Flow Control • Capital Expenditure Control • Reserve Replacement Goals • Production Goals • Finding Costs Control • Dry Hole Expectations Control • Reserve Goals • Net Profit Goals
Hospital Emergency Room Process Patient Arrival Emergency Room (ER) Admit Treatment Objective = minimize expected total asset cost while ensuring a reasonable average patient cycle time Approach= optimize current process, redesign process and re-optimize. Release Joseph DeFee, CACI, Inc.
ER Resources • Nurses • Physicians • Patient Care Technicians (PCTs) • Administrative Clerks • Emergency Rooms (ER)
Problem • Minimize E[Total Asset Cost] • Subject to: • E[Cycle Time] for Level 1 Patients < 2.4 hours • Number of Nurses between 1 and 7 • Number of Physicians between 1 and 3 • Number of PCTs between 1 and 4 • Number of Clerks between 1 and 4 • Number of ER between 1 and 20
Solution • Set up OptQuest to run for 100 iterations and 5 runs per iteration • Each run simulates 5 days of ER operation • Results: • Best solution found in 6 minutes • E[TAC] = $ 25.2K (31% improvement) • E[CT] for P1 = 2.17 hours
Process Redesign Possible to improve E[CT] for P1 even further? Transfer to room Y OK? Arrive at ER Receive treatment Fill out registration Released N Admitted Into Hospital Current Process Receive treatment Transfer to room OK? Y Arrive at ER Released Fill out registration N Admitted Into Hospital Redesigned Process
Solution of the Redesigned Process • Set up OptQuest to run for 100 iterations and 5 runs per iteration • Each run simulates 5 days of ER operation • Results: • Best solution found in 8 minutes • E[TAC] = $ 24.6K (new best, 3.4% improvement) • E[CT] for P1 = 1.94 hours (12% improvement)
Conclusions Simulation Optimization with OptQuest is able to • fully address uncertainty from multiple sources • find high-quality solutions in reasonable time • follow modified models and re-optimize them • handle problems that are not solvable by classical methods
Global Conclusions - 1 These applications are only a fraction of the ways that metaheuristics and simulation are used in optimization involving non-linearity and uncertainty Over 60,000 user licenses of the system have been sold (each licensed user might have multiple kinds of problems)
Global Conclusions - 2 Key methodology is anintegration of: Adaptive Memory Metaheuristics (TS) Evolutionary Metaheuristics Math Programming Data Mining (Pattern Analysis)
Wave of Future Bootstrapping (Mutual Iterated Design): Metaheuristics (Sim Opt) Tuning (parameters) and Tailoring General Non-linear Models/Methods General Mixed Integer Models/Methods Knowledge Representation by Meta-Models