测测你的软件度量知识

和大家分享下“软件度量”课的期末考试题(加上中文)，也许你可以用它来测测自己的软件度量知识，欢迎留下你的答案。

Problem 1 (15 points):简短答案问题 Short Answers

Your answers should be short and to the point.

a.给出两个发布后用户报告缺陷的属性，这两个属性用来做什么？

Name two attributes for “defect” reported by end users after software release, what can the attributes be used for?

b.为何SPC用于软件开发项目时，会使用XmR控制图而非XandR控制图？

Why XmR Chart not XandR Chart is mostly used in SPC analysis for software development projects?

c. 比尔·盖茨指出“<span style=”font-family:SimSun;mso-bidi-font-family:
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Bill Gates points out “Measuring software productivity by lines of code is like measuring progress on an airplane by how much it weighs.” Do you agree with him? Justify your answer.

d. 选择刻画过程性能的度量准则如下：

Common criteria for measures used to characterize process performance are given below.

选择一个度量指标刻画需求评审过程的性能，请使用上面7个准则评估下你选的度量。

You are asked to define a measure to characterize the performance of the software requirement review process, please the 7 criteria given above to assess the measure of your choice.

e.如何使用下面的状态表，帮助你规划组织度量体系的增量建立？

How can the status table given below help you better plan the implementation of your organization’s measurement program incrementally?

Problem 2 (15 points): （使用GQM（目标–问题–度量）框架）(The Use of Goal-Question-Metric (GQM) Paradigm)

下面是建立GQM的步骤和一个评估编码规范是否有效的例子。

A measurement program can be successful if it is designed with goals of the project in mind.  The GQM approach provides a framework involving three steps:

1.List the major goals of the software project.

2.Derive from each goal the questions that must be answered to determine if the goals are being met.

3.Decide what must be measured to be able to answer the questions adequately.

By deriving the measurement this way, it becomes clear how to use the resulting data. As an example, Figure below show how several metrics might be generated from a single goal.

Goal:

如果你在管理一个系统可靠性要求较高的软件项目，测试阶段发现一系列缺陷，你担心不能按期交付符合质量要求的软件。请构建一个GQM树，帮助你做是否可以交付软件的决策。请解释清楚为何所建的GQM树可以帮助做出比较靠谱的决定。

Suppose you are managing a software development project for which reliability is a major concern. A continual stream of defects is discovered in the software during the testing phase, and you suspect that the software will not be of sufficient quality by the shipping deadline. Construct a GQM tree (like the one given above) that will help you make an informed decision about when to ship the software. Clearly justify why the tree you have built can help you make this decision?

Problem 3 (20 points):  规划一个度量方案Set Up a Measurement Program

如下图所示，规划度量活动主要包含三方面的内容：识别过程问题，选择和定义度量指标，将其融入软件过程中。

Three principal activities of measurement planning are: identify process issues, select and define measures, integrate with software process.

考虑下列场景：你的软件团队开始使用2周一个迭代，以Scrum为主的敏捷开发模式。几个迭代后，团队面临一些问题：不能按期完成迭代列表中的一些用户故事，修复之前迭代发布功能的缺陷占用了团队不少资源等。你被要求规划一个度量方案，帮助监控、改进团队研发效能。遵循上面三个步骤中的活动以及在本学期课程中学到的方法，制定一个度量计划。如需要，可以做些必要的假设。

Consider the following scenario: your team just started Scrum based agile development mode and two-weeks sprint is used. After a few sprints, the team experienced the following problems: some user stories placed in sprint backlog cannot be completed at the end of a sprint, fixing bugs found previous releases reduces team’s capacity to develop new features, etc. You are asked to establish a measurement program that can be used to monitor and improve the software teams’ productivity. By following the activities given in the three steps and what you have learnt in the class, develop a plan to establish such a measurement program. The plan should cover the key activities in the three stages. Make necessary assumptions if necessary.

Problem 4(15 points): XmR控制图 XmR Chart

下表记录了对新系统20个子系统需求评审发现的缺陷数。请计算出XmR的控制上下限，根据所建控制图，判断下需求评审过程是否稳定？给出具体分析并清晰地解释所推出的结论。

The following table shows the number of defects found during requirement inspections for each of 20 components of a new system. Please calculate the control limits for the XmR charts.  Based on the charts, is the process of inspection stable? Please you’re your analysis and clearly justify your conclusion.

Problem 5（20 points）通过例子回答下列问题 Answer the following questions using specific examples.

1. a.度量做得不好主要有下列四个原因

4 common reasons for our lack of success in measurement are:

– 不同度量数据使用者有不同需求

Different users of measurement data have different needs

–不同组织使用不同的实践方法

Different organizations have different established practices.

–不能清晰的解读度量结果

Unambiguous communication of measurement results is inherently difficult.

–缺乏结构化的方法沟通度量结果

Structured methods for communicating measurement results seldom exist.

给出一个例子解析上面其中的一个问题

Give one example to illustrate the issue for one of the 4 problems given above. Note only one example for one issue is needed.

1. b. Larry Page，谷歌创始人，这样评价OKRs：虽然我真的不喜欢过程，但好的想法和强大的执行力才能创造奇迹。这就是OKRs能起到的作用。

给出一个支持Page这句话的OKR的例子，给出解释。如，你个人2023年目标OKR。

Larry Page, Google founder, points out: As much as I hate process, good ideas with great execution are how you make magic. And that is where OKRs come in.

Give an example to validate Mr. Page’s statement. For example, you can define an OKR for your personal 2023 goal.

1. c. Mr. Douglas Hubbard指出：和我们直觉相反，很小的样本点也能给出满足严格数学要求，具有统计意义的结论。

给出一个例子验证Mr. Hubbard的结论。

Mr. Douglas Hubbard stated: contrary to the intuition of many, a very small sample can produce statistically significant results in its strict mathematical sense.

Give one example to validate Mr. Hubbard’s conclusion.

1. d. 延时成本（CoD）是被许多IT组织忽略的一个非常重要的度量指标。

给出一个延时成本如何帮助你做出一个重要决策的例子。

Cost of delay (CoD) is one of the most important metrics that has been ignored by IT world.
Give one example to show how CoD may be used to help you make an important decision.

Problem6: (15 points) 对错问题，解释你的答案True or False. Please JUSTIFY your answers.

1. a. CMMI Dev 1.3将MA纳入二级过程域，因为它可以用来支持2级，3级，4级，和5级过程域中的活动。

Measurement and Analysis (MA) defined in CMMI DEV V 1.3 is placed as a Level 2 PA (Process Area) because it could be used to support activities defined in PAs in Level 2, Level 3, Level 4, and Level 5.

1. b. 计算控制图上下限时，一般建议需要10到15组数据建立X-Bar and R Chart；需要25-30单点数据建立XmR chart。

When calculating control limits, it is typically recommended that 10 to 15 subgroups are needed for X-bar and R chart; and 25 to 30 individual values are needed for XmR charts.

1. c. 计算XmR chart时，数据必须按时间顺序排列。

When computing XmR charts, one must place the data based on the order of arriving time.

1. d. 当你开始度量一个过程绩效时，这个过程一定会被改进。

A process will be improved for sure if we start to measure its performance.

1. e. 跑图常常被用来帮助识别质量和其他问题的根因。

A run chart is usually used to help identifying the underlying causes of a problem or quality characteristic.