Chapter 3 Decision Analysis Prepared by Lee Revere and John Large To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna 3-1 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 Learning Objectives Students will be able to: 1. List the steps of the decision-making process. 2. Describe the types of decision-making environments. 3. Make decisions under uncertainty. 4. Use probability values to make decisions under risk. 5. Understand the importance and use of utility theory in decision theory. To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna 3-2 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 Chapter Outline 3.1 3.2 3.3 3.4 3.5 3.7 3.8 Introduction The Six Steps in Decision Theory Types of Decision-Making Environments Decision Making under Uncertainty Decision Making under Risk How Probability Values Are Estimated by Bayesian Analysis Utility Theory To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna 3-3 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 Introduction Decision theory is an analytical and systematic way to tackle problems. A good decision is based on logic. To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna 3-4 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 The Six Steps in Decision Theory 1. 2. 3. 4. Clearly define the problem at hand. List the possible alternatives. Identify the possible outcomes. List the payoff or profit of each combination of alternatives and outcomes. 5. Select one of the mathematical decision theory models. 6. Apply the model and make your decision. To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna 3-5 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 John Thompson’s Backyard Storage Sheds Define problem To manufacture or market backyard storage sheds List alternatives 1. 2. 3. Identify outcomes The market could be favorable or unfavorable for storage sheds List payoffs List the payoff for each state of nature/decision alternative combination Select a model Decision tables can be used to solve the problem Apply model and make decision Solutions can be obtained and a sensitivity analysis used to make a decision To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna Construct a large new plant A small plant No plant at all 3-6 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 Decision Table for Thompson Lumber State of Nature Alternative Favorable Unfavorable Market ($) Market ($) Construct a large plant 200,000 -180,000 Construct a small plant 100,000 -20,000 Do nothing 0 0 To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna 3-7 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 Types of DecisionMaking Environments Type 1: Decision making under certainty. Decision maker knows with certainty the consequences of every alternative or decision choice. Type 2: Decision making under risk. The decision maker does know the probabilities of the various outcomes. Decision making under uncertainty. The decision maker does not know the probabilities of the various outcomes. To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna 3-8 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 Decision Making under Uncertainty Maximax Maximin Equally likely (Laplace) Criterion of realism Minimax To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna 3-9 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 Decision Table for Thompson Lumber Maximax: Optimistic Approach Find the alternative that maximizes the maximum outcome for every alternative. State of Nature Alternative Favorable Unfavorable Market ($) Market ($) Construct a large plant 200,000 -180,000 Construct a small plant 100,000 -20,000 Do nothing 0 0 To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna 3-10 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 Thompson Lumber: Maximax Solution State of Nature Alternative Maximax Favorable Market ($) Unfavorable Market ($) Construct a large plant 200,000 -180,000 200,000 Construct a small plant 100,000 -20,000 100,000 Do nothing 0 0 0 To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna 3-11 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 Decision Table for Thompson Lumber Maximin: Pessimistic Approach Choose the alternative with maximum minimum output. State of Nature Alternative Favorable Unfavorable Market ($) Market ($) Construct a large plant 200,000 -180,000 Construct a small plant 100,000 -20,000 Do nothing 0 0 To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna 3-12 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 Thompson Lumber: Maximin Solution State of Nature Alternative Maximin Favorable Market ($) Unfavorable Market ($) Construct a large plant 200,000 -180,000 -180,000 Construct a small plant 100,000 -20,000 -20,000 Do nothing 0 0 0 To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna 3-13 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 Thompson Lumber: Hurwicz Criterion of Realism (Hurwicz) Decision maker uses a weighted average based on optimism of the future. State of Nature Alternative Favorable Market ($) Unfavorable Market ($) Construct a large plant 200,000 -180,000 Construct a small plant 100,000 -20,000 Do nothing 0 0 3-14 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna Thompson Lumber: Hurwicz Solution CR = α*(row max)+(1- α)*(row min) State of Nature Alternative Criterion of Realism or Weighted Average (α = 0.8) ($) Favorable Market ($) Unfavorable Market ($) Construct a large plant 200,000 -180,000 124,000 Construct a small plant 100,000 -20,000 76,000 Do nothing 0 0 0 To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna 3-15 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 Decision Making under Uncertainty Equally likely (Laplace) Assume all states of nature to be equally likely, choose maximum Average. State of Nature Alternative Favorable Market ($) Unfavorable Market ($) Construct a large plant 200,000 -180,000 Construct a small plant 100,000 -20,000 Do nothing 0 0 To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna 3-16 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 Decision Making under Uncertainty State of Nature Alternative Avg. Favorable Market ($) Unfavorable Market ($) Construct a large plant 200,000 -180,000 10,000 Construct a small plant 100,000 -20,000 40,000 Do nothing 0 0 0 To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna 3-17 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 Thompson Lumber; Minimax Regret Minimax Regret: Choose the alternative that minimizes the maximum opportunity loss . State of Nature Alternative Favorable Market ($) Unfavorable Market ($) Construct a large plant 200,000 -180,000 Construct a small plant 100,000 -20,000 0 0 Do nothing To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna 3-18 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 Thompson Lumber: Opportunity Loss Table State of Nature Alternative Favorable Market ($) Unfavorable Market ($) Construct a large plant 200,000 – 200,000 = 0 0- (-180,000) = 180,000 Construct a small plant 200,000 100,000 = 100,000 0- (-20,000) = 20,000 200,000 – 0 = 200000 0–0=0 Do nothing To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna 3-19 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 Thompson Lumber: Minimax Regret Solution State of Nature Alternative Maximum Opportunity Loss Favorable Market ($) Unfavorable Market ($) Construct a large plant 0 180,000 180,000 Construct a small plant 100,000 20,000 100,000 Do nothing 200,000 0 200,000 To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna 3-20 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 Decision Making under Risk Expected Monetary Value: EMV(Alternative) n Payoff S j * P( S j ) j 1 where n number of stages of nature. In other words: EMVAlternative n = Payoff 1 * PAlt. 1 + Payoff 2 * PAlt. 2 + … + Payoff n * PAlt. N EMV= payoff of state of nature* probability of state of nature To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna 3-21 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 Thompson Lumber: EMV State of Nature Alternative Construct a large plant Favorable Market ($) 200,000 Unfavorable Market ($) EMV -180,000 200,000*0.5 + (-180,000)*0.5 = 10,000 Construct a small plant 100,000 -20,000 100,000*0.5 + (-20,000)*0.5 = 40,000 Do nothing 0 0 0*0.5 + 0*0.5 = 0 Probabilities 0.50 0.50 To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna 3-22 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 Thompson Lumber: EV|PI and EMV Solution State of Nature Alternative Favorable Unfavorable Market Market ($) ($) EMV Construct a large plant 200,000 -180,000 10,000 Construct a small plant 100,000 -20,000 40,000 Do nothing 0 0 0 200,000* 0.5 = 100,000 0*0.5 = 0 EV׀PI To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna 3-23 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 Expected Value of Perfect Information (EVPI) EVPI places an upper bound on what one would pay for additional information. EVPI is the expected value with perfect information minus the maximum EMV. To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna 3-24 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 Expected Value with Perfect Information (EV|PI) n EV | PI (Best outcome for state of nature) * P(S j ) j1 n number of states of nature. In other words EV׀PI = Best Outcome of Alt 1 * PAlt. 1 + Best Outcome of Alt 2 * PAlt. 2 +… + Best Outcome of Alt n * PAlt. n To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna 3-25 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 Expected Value of Perfect Information EVPI = EV|PI - maximum EMV Expected value with no additional information Expected value with perfect information To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna 3-26 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 Thompson Lumber: EVPI Solution EVPI = expected value with perfect information - max(EMV) = $200,000*0.50 + 0*0.50 - $40,000 From previous slide = $60,000 • It means that if the cost of information less that 60000 we’ll accept to pay for getting information • Otherwise refuse. To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna 3-27 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 In-Class Example 2 Let’s practice what we’ve learned. Using the table below compute EMV, EV׀PI, and EVPI. State of Nature Good Market ($) Average Market ($) Poor Market ($) 75,000 25,000 -40,000 Construct a 100,000 small plant 35,000 -60,000 0 0 Alternative Construct a large plant Do nothing To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna 0 3-28 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 In-Class Example 2: EMV and EV׀PI Solution State of Nature Good Market ($) Average Market ($) Poor Market ($) EMV Construct a large plant 75,000 25,000 -40,000 21,250 Construct a small plant 100,000 35,000 -60,000 27,500 Do nothing 0 0 0 0 0.25 0.50 0.25 Alternative To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna 3-29 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 In-Class Example 2: EVPI Solution EVPI = expected value with perfect information - max(EMV) = $100,000*0.25 + 35,000*0.50 +0*0.25 = $ 42,500 - 27,500 = $ 15,000 To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna 3-30 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 Expected Opportunity Loss EOL is the cost of not picking the best solution. EOL = Expected Regret To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna 3-31 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 Thompson Lumber: EOL The Opportunity Loss Table State of Nature Alternative Favorable Market ($) Unfavorable Market ($) Construct a large plant 200,000 – 200,000 0- (-180,000) Construct a small plant 200,000 100,000 0 – (-20,000) Do nothing 200,000 - 0 0-0 Probabilities 0.50 0.50 To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna 3-32 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 Thompson Lumber: EOL Table State of Nature Alternative Favorable Unfavorable Market ($) Market ($) Construct a large plant 200,000 -180,000 Construct a small plant 100,000 -20,000 Do nothing 0 0 Probabilities 0.50 0.50 To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna 3-33 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458 Thompson Lumber: EOL Solution Alternative Large Plant Small Plant Do Nothing EOL (0.50)*$0 + $90,000 (0.50)*($180,000) (0.50)*($100,000) $60,000 + (0.50)(*$20,000) (0.50)*($200,000) $100,000 + (0.50)*($0) To accompany Quantitative Analysis for Management, 9e by Render/Stair/Hanna 3-34 © 2006 by Prentice Hall, Inc. Upper Saddle River, NJ 07458
© Copyright 2024 Paperzz