问题 问答题


阅读以下技术说明,根据要求回答问题1~问题4。
[说明]
系统集成商Y公司承担了某企业的信息系统项目P的开发建设工作,Y公司任命柳工为项目经理。该信息系统项目P包括A~H 8个应用子系统,其结构如图4-3所示,其中子系统D与G的业务运行依赖于公共模块E。


现计划采用自顶向下的方法执行信息系统P的测试项目,该项目包括多个作业。设作业A的任务是对模块A进行测试,作业B的任务是对模块B进行测试……依此类推。作业P的任务是对项目P进行整体测试。表4-14列出了该项目各作业计划所需的天数、至少必需的天数(即再增大花费也不能缩短的天数),以及每缩短1天测试所需增加的费用。图4-4是尚未完成的该项目计划图,其中,每条箭线表示一个测试作业,箭线上标注的字母表示作业名,数字表示计划测试天数。

表4-14 项目P测试计划表
作业计划所需的天数至少必须天数每缩短1天所需增加的费用(元)作业计划所需的天数至少必须天数每缩短1天所需增加的费用(元)
A21500F321500
B531000G542500
C742500H422000
D432000P55
E422000

如果要求该信息系统测试项目比原计划提前1天完成,则至少应增加多少费用应将哪些测试作业缩短1天

答案

参考答案:

解析:将作业A缩短1天,需要增加500元 这是一道要求读者掌握缩短项目时间与其所发生的成本之间的关系的综合分析题。本题的解答思路如下。 1) 试题要求缩短作业测试天数时所增加的费用为最小,必须缩短处于关键路径上的某些作业的完成时间才可能达到这一要求。 2) 由问题2的分析过程可知,该测试项目计划的关键路径是“

→①→②→⑤→⑥→⑦”,所涉及的作业有A、B、D、E、P。通过表4-14的第3列可知,作业A完成测试所花费的天数允许缩短1天,即由原来的2天变为1天。同理,作业B、D、E分别允许缩短2天、1天、2天的测试时间,但作业P不允许缩短测试时间。 3) 通过表4-14的第4列可知,在作业A、B、D、E中,作业A是缩短1天测试时间所需增加费用最少(500元)的作业。如果将测试作业A缩短1天,则在图4-8中路径“→①→②→⑥→⑦”所花费的时间变为18天;路径“

→①→②→⑤→⑥→⑦”所花费的时间变为19天;路径“

→①→③→④→⑥→⑦”所花费的时间变为18天,完成该测试项目计划需要19天。可见,将测试作业A缩短1天就能满足试题要求。 4) 由以上分析可知,将测试作业A缩短1天后,该测试项目计划的关键路径仍为“

→①→②→⑤→⑥→⑦”。

阅读理解

阅读理解。

     Americans love sports-they love to play them, to watch them on televisions, and to talk about them. But this hobby sometimes has serious results-at least to the players. For example, when people play tennis, sometimes they hurt their elbow and in this way they develop "tennis elbow". Also it is easy to hurt knees in

a football game. These injuries happen while the player is having fun, but they still hurt. A few months ago, Kathleen

     Simmons, who loves playing volleyball, hurt her knee in a volleyball game. Her doctor told her that she needed a very difficult operation (手术) or she might not be able to play again,

     She felt very sad and didn't know what to do. Then Simmons learned about "video operation". With the help of this new science in medicine, doctors can now repair many injuries and get people back on the playing field and back to their jobs much faster. Simmons found a hospital that was using this new science and went to see the doctors there. The doctors told her the operation could help. For this operation, her doctor didn't have to open her knee. Instead he put a very small camera lens (镜头) inside her knee. The lens sent back pictures, which appeared on a television screen. As he worked, he could see the inside of her knee

on the TV. With the help of the large pictures on the screen, the doctor knew exactly what to do when he was making the repairs.

     Simmons started walking five days after her operation. " My knee hurt a lot the first few days," she

said.  "But I felt better very quickly. " Now, six months after her operation,

     Simmons can do everything she did before her injury. "It feels like a new knee," she said.  "I can even

play volleyball again. "

根据短文内容,回答下列问题 。

1. Do Americans love sports?

    ___________________________________________

2. What sport is Simmons interested in?

    ___________________________________________

3. What did the doctor put inside Simmons' knee?

    ___________________________________________

4. What problem may people have when they play sports?

    ___________________________________________

5. What's the advantage of the new science?

    ___________________________________________

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