问题 问答题

现在有一个项目要推广,有关部门要对这两个方案作出选择。假设甲方案成功的概率是 80%,失败的概率是20%,成功能节约预算20万元,失败会损失50万元;乙方案成功的概率是50%,失败的可能性也是50%,成功能节约预算40万元,失败则会损失30万元。 要求: (1) 运用决策树法比较选择哪个方案好,并简要说明这种方法的步骤。 (2) 简述常用的战略筛选方法有哪些

答案

参考答案:

先作图,然后计算期望值并作比较:

 各项方案的损益期望值计算如下: 甲方案的损益期望值为:20×80%+(-50)×20%=6(万元) 乙方案的损益期望值为:40×50%+(-30)×50%=5(万元) 把两种方案的损益期望值进行比较,可以看出,甲方案的期望值较高,相对更为合算,故应选择甲方案。编制决策树的方法步骤如下: ①画出决策树。显示所有选择、结果及其价值,以及相关的概率。 ②计算决策点的期望值,向前推进制定出最佳行动方案。 每棵决策树从决策点开始,这些决策点具有决策者正在考虑的备选决策。应当为每个备选决策或方案画一根线或一根树枝。如果某个选择的结果是确定的,那么与该备选决策相应的树枝就是确定的。相反地,如果某个选择的结果是不确定的,那么必须画出各种可能的结果。在决策树中要应用特别的符号来确定决策点和不确定的结果点。经常用的符号有三角形、圆形和正方形。 由于决策树法是建立在概率论基础之上的一种决策,因此,我们在实际工作中应用这一方法时,应高度重视概率的测算,使决策更加科学、合理。 (2) 在评估战略的适宜性后,可进行战略筛选。一般来说,三种可行的战略筛选方法包括: ①情景分析法,这种方法将特定战略与一系列可能的未来结果匹配在一起,这个方法特别适用于存在高度不确定性的情况。 ②评级和评分法,这种方法按照与企业战略情况相关的一套预定因素对战略进行分级。 ③决策树法。使用决策树,可将复杂的问题分解成一系列简单的问题,同时使决策者能在问题的每个阶段取得相关的专家意见。这个方法通过淘汰其他战略来对各种战略进行分级。淘汰过程中应识别几个关键要素和未来将采用的发展方向。

阅读理解

阅读理解。

       The Wilsons decided to go overseas for vacation. They had a family meeting to plan the vacation.

       "First," Mr Wilson said, "we should decide where we are going."

       "I don't agree," Mrs Wilson said,"I think we should decide when we are going first. We don't want to

go to places when they are cold."

        Mr Wilson agreed, so the family's first decision was when to go on vacation. They decided to go in

July.      

         "Now we can decide where to go," said Mr Wilson.

         "But, Dad," Ben said, "don't you think that where we go depends on (依赖,取决于) how we go? If

we plan to fly, we can go a long way. If we plan to drive, we can't go far.

         "Again, Mr Wilson agreed, and they discussed this. At last they agreed to travel by plane.

         And so the planning meeting went on. The next day, one of Mr Wilson's friends at work asked, "Where

are you going for vacation?"

         "Well," Mr Wilson told him,"we are going in summer by plane, but I don't know where we are going!"

1. Why did the Wilsons have a family meeting? 

    ____________________________________

2. What did they decide first? 

    ____________________________________

3. When did they decide to go?

    ____________________________________

4. How did the Wilsons decide to travel? 

   ____________________________________

5. What they didn't decide? 

    ____________________________________

名词解释