1 介绍
1.1 目的
这本指导书讲述了如何识别和定义软件度量来支持你们自己组织的商业目标。我们要讲解的这个过程会提供深入对于你们来说最重要的管理的洞察力。这些度量能够追溯到你们的商业目标,因此你们的数据收集活动会更好地集中在他们既定的目标上。
我们把这个过程称之为"目标驱动度量"。在目标驱动度量中,首要的问题不是"我应当运用什么指标?",而是"什么是我想要知道的或要学习的?"[引自r ombach 89]
2 基础
2.1 为什么度量
度量软件过程,产品和资源有四个理由:
为了提取特征 to characterize
为了评价 to evaluate
为了预测 to predict
为了提高 to improve
我们提取特征,来获得对过程,产品,资源和环境的理解;来建立可供未来评估作比较的基线。
2.2 度量元素
通过度量这个过程,数值或象征信号被分配到现实中的实体的属性上,按照清淅定义的规则得到这些属性的特征[fenton95]。度量要求:
实体(所关心的对象)
属性(实体的特征)
标识属性值的尺度(和计量单位)
总之,属性的分类或数量是我们要度量的东西。
这意味着,在我们开展度量之前,我们必须清淅地识别实体,下文要讲述属性和我们用于标识属性值的计量单位。
figures 2-1 through 2-3 显示了软件企业产生、使用或管理的实体的例子。
2.3 客观和主观的度量
在一些圈子中有这样一种趋势,认为所有的度量都应当是客观的。我们强烈表示不同意。坚持客观会遗失这一点,就是客观和主观度量经常表述基本的不同需要。而且,实际情况是不客观的,而是主观的,一致,可重复的,最小化度量的错误和噪声。
3 一个识别和定义软件度量的过程模型
本章提供了目标驱动度量模型的概况和实施路径,详细的说明会在第四章。在目标驱动的度量中要强调的是,当收集有助于达到商业目标的信息时,和当保持度量与商业目标一致的跟踪能力时,度量本身的工作量是不能够不清不楚的。
this chapter provides an overview and roadmap for the goal-driven measurement process
that we describe in chapter 4. the emphasis throughout goal-driven measurement is on
gathering information that helps you achieve your business goals-and on maintaining
traceability from measures back to business goals, so that measurement efforts do not
wander astray.
目标驱动度量过程的结构来自于由victor basili and dieter rombach [basili 88, basili 89, rombach 89].报告的想法和经验。
这个过程的动力学和几个图解来源于由ami esprit project [ami 92, pulford 96]开发的度量过程指南。
the structure of the goal-driven measurement process draws extensively on ideas and
experience reported by victor basili and dieter rombach [basili 88, basili 89, rombach 89].
the process dynamics and several of the illustrations that we use have their origins in
measurement process guidelines developed by the ami esprit project [ami 92, pulford 96].
the goal-driven measurement process also incorporates experience that we have gained at
the software engineering institute in designing and using checklist-based frameworks for
defining software measures and communicating measurement results [florac 92, goethert
92, park 92, sei 96].
3.1 总览:概念和过程步骤overview: the precepts and the process steps
cmu/sei-96-hb-002 15
目标驱动的度过程基于三个概念,包括10个步骤。
这三个概念是
度量目标是来自于商业目标
由模型来获得度量的环境和焦点
gq(i)m把非正式的目标变成可操作的度量结构。
gq(i)m是目标(goal)问题(question)(指标)(indicator)-度量(measure)的首字母缩写。这个插入的"i"使得这与相近的gqm区别开来。
the goal-driven measurement process is based on 3 precepts, and it consists of 10 steps.
the three precepts are
o measurement goals are derived from business goals.
o evolving mental models provide context and focus.
o gq(i)m1 translates informal goals into executable measurement structures.
十个步骤是:
1, 识别商业目标
2, 识别你要学习或知道的东西
3, 识别你的子目标
4, 识别与子目标相关的实体和属性
5, 公式化你的度量目标
6, 识别量化的问题和相关的指标,这些会用于实现你的度量目标
7, 识别用于获得指标的要收集的数据元素,这些个指标是可以帮助你回答上述问题
8, 定义度量的使用,使得这些定义具有可操作性
9, 识别你使用度量的行动
10, 准备一个计划来实施度量
the 10 steps are
1. identify your business goals.
1 gq(i)m is an acronym for goal-question-(indicator)-measure. the "i" in parentheses distinguishes
this from the closely related gqm methodology introduced and described by basili and rombach
[basili 88, basili 89, rombach 89]. our use of gq(i)m is described in sections 4.5-4.8.
2. identify what you want to know or learn.
3. identify your subgoals.
4. identify the entities and attributes related to your subgoals.
5. formalize your measurement goals.
6. identify quantifiable questions and the related indicators that you will use to
help you achieve your measurement goals.
7. identify the data elements that you will collect to construct the indicators
that help answer your questions.
8. define the measures to be used, and make these definitions operational.
9. identify the actions that you will take to implement the measures.
10. prepare a plan for implementing the measures.
4 实施目标驱动过程
4.1 识别你们的商业目标
4.2 识别你要学习或知道的东西