这里在把TMMI的5个等级赘述一遍，因为它太重要了。理解它们对后面的理解很重要
2.2 Level 1 Initial At TMMi level 1, testing is a chaotic, undefined process and is often considered a part of debugging. The organization usually does not provide a stable environment to support the processes. Success in these organizations depends on the competence and heroics of the people in the organization and not the use of proven processes. Tests are developed in an ad hoc way after coding is completed. Testing and debugging are interleaved to get the bugs out of the system. The objective of testing at this level is to show that the software runs without major failures. Products are released without adequate visibility regarding quality and risks. In the field, the product often does not fulfil its needs, is not stable, and/or is too slow. Within testing there is a lack of resources, tools and well-educated staff. At TMMi level 1 there are no defined process areas. Maturity level 1 organizations are characterized by a tendency to over commit, abandonment of processes in a time of crises, and an inability to repeat their successes. In addition products tend not to be released on time, budgets are overrun and delivered quality is not according to expectations.
第一级，初始级别，测试是混乱的，无定义的过程，经常被认为是调试的一部分。组织通常不会提过稳定的环境来支持测试过程。组织的成功通常依赖组织成员的能力和英雄主义，而不是使用已经证明的流程。测试是在代码完成之后一个随机的行为。测试和调试交叉进行来找出系统bug。这个阶段的测试目标是为了展示软件没有大的失败。产品发布没有见过充分的关于质量和风险的验证。在这个领域，产品通常不满足需求,不稳定，或者很慢。对于测试而言，通常缺少资源，工具，和接受过培训的员工。在TMMI1阶段没有定义过程域。成熟度1组织通常具有的特点是有过分犯错的趋势，出现危机放弃过程，不具备重复成功的能力。另外产品趋向于不能按时发布，超预算，未按照预期发布高质量产品。
2.3 Level 2 Managed At TMMi level 2, testing becomes a managed process and is clearly separated from debugging. The process discipline reflected by maturity level 2 helps to ensure that proven practices are retained during times of stress. However, testing is still perceived by many stakeholders as being a project phase that follows coding. In the context of improving the test process, a company-wide or program-wide test strategy is established. Test plans are also developed. Within the test plan a test approach is defined, whereby the approach is based on the result of a product risk assessment. Risk management techniques are used to identify the product risks based on documented requirements. The test plan defines what testing is required, when, how and by whom. Commitments are established with stakeholders and revised as needed. Testing is monitored and controlled to ensure it is going according to plan and actions can be taken if deviations occur. The status of the work products and the delivery of testing services are visible to management. Test design techniques are applied for deriving and selecting test cases from specifications. However, testing may still start relatively late in the development lifecycle, e.g., during the design or even during the coding phase. In TMMI level 2 testing is multi-level: there are component, integration, system and acceptance test levels. For each identified test level there are specific testing objectives defined in the organization-wide or program-wide test strategy. The processes of testing and debugging are differentiated. The main objective of testing in a TMMi level 2 organization is to verify that the product satisfies the specified requirements. Many quality problems at this TMMi level occur because testing occurs late in the development lifecycle. Defects are propagated from the requirements and design into code. There are no formal review programs as yet to address this important issue. Post code, execution-based testing is still considered by many stakeholders the primary testing activity. The process areas at TMMi level 2 are: 2.1 Test Policy and Strategy 2.2 Test Planning 2.3 Test Monitoring and Control。2.4 Test Design and Execution 2.5 Test Environment
第一级别，可管理级别。测试变成一个可管理的过程并且和调试清楚的分开。成熟度级别2所反映出来的过程管理是为了保证在压力下保持已证明的实践被执行。然而，测试仍然被认为放在代码以后。为了提高测试过程，一个公司界别或者项目级别的测试策略被建立。测试计划被开发出来，通过测试计划测试方案被定义。测试方案是基于产品的风险评估的。风险管理技术被使用来确认产品的是否满足文档需求。测试计划定义了测什么，什么时候测，怎么测，由谁来测，建立承诺机制并且按照需求修改。测试被监视和管理来保证它按照测试计划进行并且如果有偏离行为时有相应的处理。产品的测试过程和测试服务发布对于管理是可见的。测试设计技术被应用到测试用例设计中。然而，测试仍然是在产品开发的后期。在tmmi2，测试是分为多个级别的。单元测试，集成测试，系统测试，可接受的测试。对于不同的测试等级，我们有相应的测试目标。
2.1 测试方针和策略
2.2测试计划
2.3测试监督和控制
2.4测试设计和执行
2.5测试环境
2.4 Level 3 Defined At TMMi level 3, testing is no longer confined to a phase that follows coding. It is fully integrated into the development lifecycle and the associated milestones. Test planning is done at an early project stage, e.g., during the requirements phase, and is documented in a master test plan. The development of a master test plan builds on the test planning skills and commitments acquired at TMMi level 2. The organization’s set of standard test processes, which is the basis for maturity level 3, is established and improved over time. A test organization and a specific test training exist, and testing is perceived as being a profession. Test process improvement is fully institutionalized as part of the test organization’s accepted practices. Organizations at level 3 understand the importance of reviews in quality control; a formal review program is implemented although not yet fully linked to the dynamic testing process. Reviews take place across the lifecycle. Test professionals are involved in reviews of requirements specifications. Whereas the test designs at TMMi level 2 focus mainly on functionality testing, test designs and test techniques are expanded at level 3 to include nonfunctional testing, e.g., usability and/or reliability, depending on the business objectives. A critical distinction between TMMi maturity level 2 and 3 is the scope of the standards, process descriptions, and procedures. At maturity level 2 these may be quite different in each specific instance, e.g., on a particular project. At maturity level 3 these are tailored from the organization’s set of standard processes to suit a particular project or organizational unit and therefore are more consistent except for the differences allowed by the tailoring guidelines/ This tailoring also enables valid comparisons between different implementations of a defined process and easier movement of staff between projects . Another critical distinction is that at maturity level 3, processes are typically described more rigorously than at maturity level 2. Consequently at maturity level 3, the organization must revisit the maturity level 2 process areas.The process areas at TMMi level 3 are: 3.1 Test Organization 3.2 Test Training Program 3.3 Test Lifecycle and Integration 3.4 Non-functional Testing 3.5 Peer Reviews
第三级别，已定义级别。测试不再是代码之后的一个阶段。它被完全的集成到开发生命周期和相应里程碑中。测试计划在项目早期建立。比如在需求阶段，以文档存在于测试计划中。组织建立了标准的测试流程。这个流程是建立在成熟度3级别的。被建立和不断提升。测试组长和测试培训存在。测试被要求专业。过程提升被组织接受并作为制度的一部分。TMMI3明确了质量管理复查的重要性。审查在整个生命周期存在。TMMI3会关注一些非功能性的测试。包括可用性和稳定性测试。TMMI2和TMMI3的一个主要区别是测试标准和过程描述执行的范围。【备注：TMMI3主要区别TMMI2的地方，测试贯穿整个开发周期，引入非功能性测试，测试标准和行为的范围从项目扩展到公司级别】
3.1 测试组织
3.2测试培训计划
3.3测试生命周期和集成
3.4非功能性测试
3.5 互相审查