You are the maintenance engineer for your company. You are just about to leave on your vacation for two
- You are the maintenance engineer for your company. You are just about to leave on your vacation for two weeks, and your boss is concerned about certain machines that have been somewhat unreliable, requiring your expertise to keep them running. Your boss has asked you how many of these machines you expect to fail while you are out of town. You have made the following subjective judgments:
- There is a 0.5 chance that none of the machine will fail;
- There is an approximately 0.15 chance that two or more will fail; and
- There is virtually no chance that four or more will fail.
Being impatient with this slow assessment procedure, you decide to try to fit a theoretical distribution.
- Many operations researcher would use a Poisson distribution in this case. Why might the Poisson be appropriate in this case?
- Find a Poisson distribution that provides a good representation of your assessed beliefs. Give a specific value for the parameter m. According to the distribution, what is the expected number of machines that will break down during your absence? (Hint: Look in the table for the Poisson distribution)
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Looking at the information you provide, your boss, however, thinks you are
somewhat optimistic, so he decides to assign a Poisson distribution with m=1 to the occurrence of machine breakdowns during your two-week vacation. Now the boss has a decision to make. He can either close the plant involving the machines in question at cost of $10,000, or he can leave that plant up and running. Of course, if there is no machine failure, there is no cost. If there is only one failure, he can work with the remaining equipment until you return, so the cost is effectively zero. If there are two or more machine failures, however, there will be assembly time lost, and he will have to call in experts to repair the machine immediately. The cost would be $15,000. What should he do? - Find the EVPI concerning the number of machine failures during your absence.
2. [30 Points] Daniel has a research-and-development decision to make based on two alternative projects A and B. However, he can choose only one of the two projects due to budget constraints. The payoffs of these projects depend on the degree of success of their development, as shown in the decision tree in Figure 2.1.
Daniel has made the following assessments of utility values:
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If he had the choice, he would be indifferent between alternatives M and N shown in Figure 2.2
. - If he had the choice, he would be indifferent between alternatives M’ and N’ shown in Figure 2.3.
- [20 Points] According to the assessments i) and ii), which project should Daniel choose based on the maximum expected utility. Justify your answer. (Hint: set the utilities of the best and worst consequences in the decision tree to 1 and 0, respectively)
- [10 Points] What kind of risk attitude is Daniel demonstrating in this decision? Why?