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Continual Improvement Improvement Using Simulation. Gordon Clark Clark Solutions, Inc. The Ohio State University. Objectives. Simulation use in Six Sigma Lean Design for Six Sigma Validation of simulation models Relation with designed experiments. Simulation. Imitates the system
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Continual ImprovementImprovement Using Simulation Gordon Clark Clark Solutions, Inc. The Ohio State University Lexington ASQ Section
Objectives • Simulation use in • Six Sigma • Lean • Design for Six Sigma • Validation of simulation models • Relation with designed experiments Lexington ASQ Section
Simulation • Imitates the system • Production line • Experiments Lexington ASQ Section
Simulation in Quality Improvement • Lean Six Sigma • Measure Phase • Determine KPIVs • Value Stream Map • Compare with real system • Improvement Phase • Reduce physical experimentation • Identify process changes • Design for Six Sigma Lexington ASQ Section
Emphasis by American Society for Quality (ASQ) • CSSBB BOK • Prior to 2007 • 2007 • Certified Six Sigma Black Belt Handbook (2005) • Breyfogle (2003). Implementing Six Sigma • The Quality Toolbox (2005) Lexington ASQ Section
Simulation Model Validation • Robert Sargent (2010) • Model purpose • Range of accuracy for successful validation • Conceptual model • Experts examine graphical model • Traces to track entities • Computer model • Operational validation Lexington ASQ Section
Operational Validity Lexington ASQ Section
Simulation-Based LSS Process Define Project Scope Define CTQ and Lean Measures Define Structure and Variables Define Develop Current State VSM Develop Simulation Conceptual Model Develop Simulation Model Measure View traces or an Animated Simulation Model Identify KPIVs and KPOVs Analyze Lexington ASQ Section
Simulation-Based LSS Process Measure Develop DOE Plan and Design Run Simulation Experiments Analyze Process Flow Analyze Optimize Process Parameters Develop Future State VSM Improve Control Lexington ASQ Section
Simulation-Based LSS Process Improve Develop Control Strategy Implement Control Plans Monitor Performance Over Time Control Simulation Predictions Accurate? Modify Simulation Model No Analyze Yes Continue Monitoring B. El-Haik and R. Al-Aormar (2006). Simulation-Based Lean Six-Sigma and Design for Six-Sigma Lexington ASQ Section
Simulation Model Validity • Compare output with actual data • Verify architecture with operating personnel • S. J. Shim and A. Kumar (2010). Business Process Management Patient Wait Times (Minutes) Lexington ASQ Section
Emergency Department Case Study • Paul, J. A. and L. Lin (2007). Society for Health Systems Conference • Simulation-based Lean Six Sigma • 40 minute reduction in length of stay • Adding one ED physician • Reducing admit time • Shortening lab turn-around time Lexington ASQ Section
Simulation Concepts • Dynamic entities • Inputs • Attributes • Activities • Delays • Queueing • Resources • Random variable generation Lexington ASQ Section
Moderate Acuity Process Bed Placement Clerk Discharge Patient Arrives I ns i de E D RN & MD Assessment Lab Tests Triage Discharge or Admit RN & MD Procedure Register RN & MD Discharge E. Beck, H. Balsubramanian, P. Henneman (2009). Proceedings of the 2009 Winter Simulation Conference Lexington ASQ Section
Severe Acuity Process Bed Placement Patient Arrives I ns i de E D RN & MD Assessment Lab Tests Triage Admit RN & MD Procedure RN & MD Discharge Clerk Discharge Lexington ASQ Section
Low Acuity Patient Service Times C. Johnson et al (2004). IIE Annual Conference and Exhibition 2004 Lexington ASQ Section
Low Acuity Patient Service Times Lexington ASQ Section
Time 198 Lexington ASQ Section
Animation Lexington ASQ Section
Current State • Resources • 10 beds • 3 RNs • 2 MDs • Incoming patients • 2 per hour • 40% severe Lexington ASQ Section
Performance Measures Simulated 300 8 Hour Shifts Lexington ASQ Section
Current VSMResults from 300 8 Hours Shifts Triage Queue Clerk Queue Bed Queue Avg Time .97 Min Time 0 Max Time 25.6 Time Std. Dev. 2.76 Avg Length .032 Avg Time 2.27 Min Time 0 Max Time 68.21 Time Std. Dev. 5.41 Avg Length .121 Avg Time 3.34 Min Time 0 Max Time 158.8 Time Std. Dev. 15.2 Avg Length .111 RN Queue Lexington ASQ Section
Current VSMResults from 300 8 Hours Shifts Bed Queue RN Queue MD Queue Avg Time 2.07 Min Time 0 Max Time 84.1 Time Std. Dev. 6.39 Avg Length .207 Avg Time 3.88 Min Time 0 Max Time 217.2 Time Std. Dev. 10.7 Avg Length .387 Lexington ASQ Section
Summary • Modified DMAIC process for simulation-based LSS • Use of VSM • Model validation • Emergency Dept. Simulation • Accuracy of actual case study • Lengthy observation times with real system DOE Lexington ASQ Section
Emergency Department Simulation • Long waiting times • Visits increasing • Key input variables • Doctors • Patients per doctor • Nurses • Queuing Priority • Arrival time • Severity Lexington ASQ Section
Assembly of Car Engines • Design for Six Sigma • Time to market • Work stations decoupled by buffers • Options • Even distribution • Bow Tie • Findings • Even better than Bow Tie • Maximum of 2 buffers • B. Tjahjono, J. Ladbrook, J. Kay (2009). Proceedings of the 2009 Winter Simulation Conference Lexington ASQ Section
Questions • Is simulation useful in • Six Sigma • Lean • Design for Six Sigma Lexington ASQ Section