Decision Analysis - ia State University：决策分析-乔治亚州立大学.ppt

Decision AnalysisIntroductionChapter 6What kinds of problems ??Decision Alternatives (“what ifs”) are known?States of Nature and their probabilities are known (ex. rainy 20%, partly cloudy 50%, sunny 20%)?es, (referred to as “Payoffs”) putable under different possible scenarios –each is bination of a decision alternative and a state of nature Decision Analysis Basic Terms?Decision Alternatives ?States of Nature (eg. Condition of economy or weather)?Payoffs ($ e of a choice assuming a state of nature)?Criteria (. Expected Value)Decision Analysis Conditions?Certainty–Decision Maker knows with certainty what the state of nature will be - only one possible state of nature?Ignorance–Decision Maker knows all possible states of nature, but does not know probability of occurrence ?Risk–Decision Maker knows all possible states of nature, and can assign probability of occurrence for each state –this will be our focusDecision Making Under CertaintyDecision VariableUnits to build150Parameter EstimatesCost to build (/unit)6,000$ Revenue (/unit)14,000$ Demand (units)250Consequence VariablesTotal Revenue2,100,000$ Total Cost900,000$ Performance Revenue1,200,000$ Decision Making Under Ignorance – Payoff TableKelly Construction Payoff Table (Prob. 8-17)Low (50 units)Medium (100 units)High (150 units)Build 50400,000400,000400,000Build 100100,000800,000800,000Build 150(200,000)500,0001,200,000State of NatureDemandAlternative ActionsDecision Making Under IgnoranceWhich alternative will we choose??Maximax–Select the strategy with the highest possible return?Maximin–Select the strategy with the smallest possible lossMaximax: The Optimistic Point of View?Select the “best of the best” strategy–Evaluates each decision by the maximum possible return associated with that decision (Note: if cost data is used, the minimum return is “best”)–The decision that yields the maximum of these maximum returns (maximax) is then selected?For “risk takers”–Doesn’t consider the “down sid