Behavioral Characteristics of the TMM Levels

Level 1 - Initial: Testing is a chaotic process; it is ill-defined and not distinguished from debugging.
Tests are developed in an ad hoc way after coding is done. Testing and debugging are interleaved to get
the bugs out of the software. The objective of testing is to show that the software works [1]. Software
products are released without quality assurance. There is a lack of resources, tools, and properly trained
staff. This type of organization would be on Level 1 of the Capability Maturity Model (CMM) developed
by the Software Engineering Institute. There are no maturity goals at this level.

第一级  初始级
TMM初始级软件测试过程的特点是测试过程无序，有时甚至是混乱的，几乎没有妥善定义的。初始级中软件的测试与调试常常被混为一谈，软件开发过程中缺乏测试资源，工具以及训练有素的测试人员。初始级的软件测试过程没有定义成熟度目标。

Level 2 - Phase Definition: Testing is separated from debugging and is defined as a phase that follows
coding. It is a planned activity; however, test planning at Level 2 may occur after coding for reasons
related to the immaturity of the test process. For example, at Level 2 there is the perception that all testing
is execution-based and dependent on the code, and therefore it should be planned only when the code is
complete.
The primary goal of testing at this level of maturity is to show that the software meets its specifications
[2]. Basic testing techniques and methods are in place. Many quality problems at this TMM level occur
because test planning occurs late in the software lifecycle. In addition, defects propagate into the code
from the requirements and design phases, as there are no review programs that address this important
issue. Post-code, execution-based testing is still considered the primary testing activity.

第二级  定义级
TMM的定义级中，测试己具备基本的测试技术和方法，软件的测试与调试己经明确地被区分开。这时，测试被定义为软件生命周期中的一个阶段，它紧随在编码阶段之后。但在定义级中，测试计划往往在编码之后才得以制订，这显然有背于软件工程的要求。
TMM的定义级中需实现3个成熟度目标:制订测试与调试目标，启动测试计划过程，制度化基本的测试技术和方法。

Level 3 - Integration: Testing is no longer a phase that follows coding; it is integrated into the entire
software lifecycle. Organizations can build on the test planning skills they have acquired at Level 2.
Unlike Level 2, planning for testing at TMM Level 3 begins at the requirements phase and continues
throughout the lifecycle supported by a version of the V-model [3]. Test objectives are established with
respect to the requirements based on user and client needs and are used for test case design and success
criteria. There is a test organization, and testing is recognized as a professional activity. There is a
technical training organization with a testing focus. Basic tools support key testing activities. Although
organizations at this level begin to realize the important role of reviews in quality control, there is no
formal review program, and reviews do not yet take place across the lifecycle. A test measurement
program has not yet been established to qualify process and product attributes.

第三级  集成级

在集成级，测试不仅仅是跟随在编码阶段之后的一个阶段，它已被扩展成与软件生命周期融为一体的一组已定义的活动。测试活动遵循软件生命周期的V字模型。测试人员在需求分析阶段便开始着手制订测试计划，并根据用户或客户需求建立测试目标，同时设计测试用例并制订测试通过准则。在集成级上，应成立软件测试组织，提供测试技术培训，关键的测试活动应有相应的测试工具予以支持。在该测试成熟度等级上，没有正式的评审程序，没有建立质量过程和产品属性的测试度量。集成级要实现4个成熟度目标，它们分别是:建立软件测试组织，制订技术培训计划，软件全寿命周期测试，控制和监视测试过程。

Level 4 - Management and Measurement: Testing is a measured and quantified process. Reviews at all
phases of the development process are now recognized as testing and quality control activities. Software
products are tested for quality attributes such as reliability, usability, and maintainability. Test cases from
all projects are collected and recorded in a test case database to test case reuse and regression testing.
Defects are logged and given a severity level. Deficiencies in the test process are now often due to the
lack of a defect prevention philosophy and the porosity of automated support for the collection, analysis,
and dissemination of test-related metrics.

第四级  管理和测量级
在管理和测量级，测试活动除测试被测程序外，还包括软件生命周期中各个阶段的评审，审查和追查，使测试活动涵盖了软件验证和软件确认活动。根据管理和测量级的要求，软件工作产品以及与测试相关的工作产品，如测试计划，测试设计和测试步骤都要经过评审。因为测试是一个可以量化并度量的过程。为了测量测试过程，测试人员应建立测试数据库。收集和记录各软件工程项目中使用的测试用例，记录缺陷并按缺陷的严重程度划分等级。此外，所建立的测试规程应能够支持软件组终对测试过程的控制和测量。管理和测量级有3个要实现的成熟度目标:建立组织范围内的评审程序，建立测试过程的测量程序和软件质量评价。


Level 5 - Optimization, Defect Prevention, and Quality Control: Because of the infrastructure
provided by the attainment of maturity goals at Levels 1 through 4 of the TMM, the testing process is
now said to be defined and managedits cost and effectiveness can be monitored. At Level 5, there are
mechanisms that fine-tune and continuously improve testing. Defect prevention and quality control are
practiced. The testing process is driven by statistical sampling, measurements of confidence levels,
trustworthiness, and reliability. There is an established procedure to select and evaluate testing tools.
Automated tools totally support the running and rerunning of test cases, providing support for test case
design, maintenance of test-related items, defect collection and analysis, and the collection, analysis, and
application of test-related metrics.

第五级  优化，预防缺陷和质量控制级
由于本级的测试过程是可重复，已定义，已管理和己测量的，因此软件组织能够优化调整和持续改进测试过程。测试过程的管理为持续改进产品质量和过程质量提供指导，并提供必要的基础设施。质量控制在本级，软件组织通过采用统计采样技术，测量组织的自信度，测量用户对组织的信赖度以及设定软件可靠性目标来推进测试过程。为了加强软件质量控制，测试组和质量保证组要有负责质量的人员参加，他们应掌握能减少软件缺陷和改进软件质量的技术和工具。