Sensitive Analysis
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An Introduction to Sensitivity Analysis
Prepared for the MIT System Dynamics in Education Project Under the Supervision of Dr. Jay W. Forrester
by Lucia Breierova Mark Choudhari September 6, 1996 Vensim Examples added October 2001
Copyright © 2001 by the Massachusetts Institute of Technology
Permission granted to distribute for non-commercial educational purposes
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Table of Contents
1. ABSTRACT 46
2. INTRODUCTION
47
3. EXPLORATORY EXERCISES 3.1 EXPLORATION 1: LEMONADE STAND 3.1.1 EXERCISE 3.1.2 DEBRIEF 3.2 EXPLORATION 2: EPIDEMICS 3.2.1 EXERCISE 3.2.2 DEBRIEF
48 48 51 55 55 57 62
4. INDEPENDENT EXPLORATION: COFFEEHOUSE 4.1 CHOOSING PARAMETERS FOR SENSITIVITY ANALYSIS 4.2 PERFORMING SENSITIVITY TESTS
62 65 65
5. CONCLUSION
66
6. SUGGESTED SOLUTIONS TO SECTION 4 6.1 SOLUTION TO SECTION 4.1 6.2 SOLUTION TO SECTION 4.2 6.3 DEBRIEF
67 67 67 74
7. APPENDIX: MODEL DOCUMENTATION 7.1 LEMONADE STAND MODEL 7.2 EPIDEMICS MODEL 7.3 COFFEEHOUSE MODEL
75 75 76 77
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7. VENSIM EXAMPLES
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Abstract This paper is an introduction to a series of papers on sensitivity analysis. It contains three exploratory exercises demonstrating the effects of various parameter and initial value changes on system behavior. The paper assumes that the reader is able to build and understand a multiple-level model, and has experience with the sensitivity feature in the STELLA software.1 We encourage the reader to build all the models and to run the simulations described.
For a review of the sensitivity feature in STELLA, please refer to your STELLA user manual or to Road Maps 3: A Guide to Learning System Dynamics (D-4503-3), System Dynamics in Education Project, System Dynamics Group, Sloan School of Management, Massachusetts Institute of Technology, p. 12-13. STELLA is a registered trademark of High Performance Systems, Inc.
1
41
An Introduction to Sensitivity Analysis
Prepared for the MIT System Dynamics in Education Project Under the Supervision of Dr. Jay W. Forrester
by Lucia Breierova Mark Choudhari September 6, 1996 Vensim Examples added October 2001
Copyright © 2001 by the Massachusetts Institute of Technology
Permission granted to distribute for non-commercial educational purposes
42
D-4526-2
D-4526-2
43
Table of Contents
1. ABSTRACT 46
2. INTRODUCTION
47
3. EXPLORATORY EXERCISES 3.1 EXPLORATION 1: LEMONADE STAND 3.1.1 EXERCISE 3.1.2 DEBRIEF 3.2 EXPLORATION 2: EPIDEMICS 3.2.1 EXERCISE 3.2.2 DEBRIEF
48 48 51 55 55 57 62
4. INDEPENDENT EXPLORATION: COFFEEHOUSE 4.1 CHOOSING PARAMETERS FOR SENSITIVITY ANALYSIS 4.2 PERFORMING SENSITIVITY TESTS
62 65 65
5. CONCLUSION
66
6. SUGGESTED SOLUTIONS TO SECTION 4 6.1 SOLUTION TO SECTION 4.1 6.2 SOLUTION TO SECTION 4.2 6.3 DEBRIEF
67 67 67 74
7. APPENDIX: MODEL DOCUMENTATION 7.1 LEMONADE STAND MODEL 7.2 EPIDEMICS MODEL 7.3 COFFEEHOUSE MODEL
75 75 76 77
44
7. VENSIM EXAMPLES
D-4526-2
81
D-4526-2
45
46
D-4526-2
Abstract This paper is an introduction to a series of papers on sensitivity analysis. It contains three exploratory exercises demonstrating the effects of various parameter and initial value changes on system behavior. The paper assumes that the reader is able to build and understand a multiple-level model, and has experience with the sensitivity feature in the STELLA software.1 We encourage the reader to build all the models and to run the simulations described.
For a review of the sensitivity feature in STELLA, please refer to your STELLA user manual or to Road Maps 3: A Guide to Learning System Dynamics (D-4503-3), System Dynamics in Education Project, System Dynamics Group, Sloan School of Management, Massachusetts Institute of Technology, p. 12-13. STELLA is a registered trademark of High Performance Systems, Inc.
1