Structure of the TMMi

The structure of the TMMi is largely based on the structure of the CMMI. This is a major
benefit because many people/organizations are already familiar with the CMMI structure. The
CMMI structure makes a clear distinction between practices that are required (goals) or
recommended (specific practices, typical work products, etc.) to implement. This aspect is
also included in the TMMi. In this chapter, the components and structure of the TMMi structure
are described. In addition the support provided by the CMMI to a TMMi
implementation is described.

Required, Expected and Informative Components

The various components are grouped into three categories: required, expected and
informative.

• Required Components
  Required components describe what an organization must achieve to satisfy a process area. This achievement must be visibly implemented in an organization’s processes. The required components in TMMi are the specific and generic goals. Goals satisfaction is used in assessments as the basis for deciding if a process area has been achieved and satisfied.
• Expected Components
  Expected components describe what an organization will typically implement to achieve a required component. Expected components guide those who implement improvements or perform assessments.Expected components include both specific and generic practices. Before goals can be considered satisfied, either the practices as described or acceptable alternatives to them are present in the planned and implemented processes of the organization.
• Informative Components
  Informative components provide details that help organizations get started in thinking about how to approach the required and expected components. Subpractices, typical work products, notes, examples, and references are all informative model components.

Components of the TMMi

The TMMi model required and expected components can be summarized to illustrate their relationship as in figure 2. The following sections provide a description of the components. Note that the TMMi also provides a specific glossary of terms. The terms used in the glossary are largely re-used from the international test terminology standard developed by the International Software Testing Qualifications Board (ISTQB): Standard glossary of terms used in Software Testing [ISTQB].

• Maturity levels
  A maturity level within the TMMi can be regarded as a degree of organizational test process quality. It is defined as an evolutionary plateau of test process improvement. Each level progressively develops an important part of the organization’s test processes. There are five maturity levels within the TMMi. Each maturity level tells what to implement in order to achieve the given level. The higher the maturity level the organization is ranked at, the more mature the test process of the organization is. To reach a particular maturity level, an organization must satisfy all of the appropriate goals (both specific and generic) of the process areas at the specific level and also those at earlier maturity levels. Note that all organizations possess a minimum of TMMi level 1, as this level does not contain any goals that must be satisfied.
• Process Areas
  As stated with the exception of level 1, each maturity level consists of several process areas that indicate where an organization should focus to improve its test process. Process areas identify the issues that must be addressed to achieve a maturity level. Each process area identifies a cluster of test related activities. When the practices are all performed a significant improvement in activities related to that area will be made. In the TMMi, only those process areas are identified that are considered to be key determinants of test process capability. All process areas of the maturity level and the lower maturity levels must be satisfied to consider a maturity level to be achieved. For example, if an organization is at TMMi level 3, it has satisfied all of the process areas at both TMMi level 2 and TMMi level 3.

• Purpose
  The purpose statement describes the purpose of the process area and is an informative component. For example, the purpose statement of the test planning process area is “define a test approach based on the identified risks and the defined test strategy, and to establish and maintain well-founded plans for performing and managing the testing activities”.
• Introductory Notes
  The introductory notes section of the process area describes the major concepts covered in the process area and is an informative component.
• Scope
  The scope section of the process area specifically identifies the test practices that are addressed by the process area, and if necessary test practices that are explicitly outside the scope of this process area.
• Specific Goals
  A specific goal describes the unique characteristic that must be present to satisfy the process area. A specific goal is a required model component and is used in assessments to help determine whether a process area is satisfied.
• Generic Goals
  Generic goals appear near the end of a process area and are called ‘generic’ because the same goal statement appears in multiple process areas. A generic goal describes the characteristics that must be present to institutionalize the processes that implement a process area. A generic goal is a required model component and is used in assessments to help determine whether a process area is satisfied.
• Specific practices
  A specific practice is the description of an activity that is considered important in achieving the associated specific goal. The specific practice describes the activities expected to result in achievement of the specific goals of a process area. A specific practice is an expected model component.
• Typical Work Products
  The typical work products section lists sample outputs from a specific practice. These examples are called ‘typical work products’ because there are often work products that are just as effective but are not listed. A typical work product is an informative model component.
• Subpractices
  A subpractice is a detailed description that provides guidance for interpreting and implementing a specific practice. Subpractices may be worded as if prescriptive, but are actually an informative component meant only to provide ideas that may be useful for test process improvement.
• Generic Practices Generic practices appear near the end of a process area and called ‘generic’ because the same practice appears in multiple process areas. A generic practice is the description of an activity that is considered important in achieving the associated generic goal. A generic practice is an expected model component.
• Generic Practices Elaborations
  Generic practices elaboration appears after a generic practice in a process area to provide guidance on how the generic practice should be applied uniquely to the process area. A generic practice elaboration is an informative model component.
• Supporting Informative Components There are many places where further information is needed to describe a concept. This informative information is provided in terms of the following components:
  

  - Notes A note is a text that can accompany any other model component. It may provide detail, background, or rationale. A note is an informative model component.

  - Examples An example is a component comprising text and often a list of items, usually in a box, that a can accompany nearly any other component and provides one or more examples to clarify a concept or described activity. An example is an informative model component.

  - References A reference is a pointer to additional or more detailed information in related process areas and can accompany nearly any other model component. A reference is an informative model component.

Generic Goals and Generic Practices

This section describes all of the generic goals and generic practices. The generic goals and generic practices are largely derived from the CMMI. The generic goals are organized in numeric order. The generic practices are also organized in numerical order under the generic goal they support. Note that the generic goal from the CMMI, GG1 ‘Achieve Specific Goals’ is not taken into account since this only relates to the continuous representation of the CMMI and therefore has no relevance to the staged representation of the TMMi. Otherwise the numbering scheme of the CMMI is fully adopted to avoid confusion for organizations using both CMMI and TMMi.

The capability level you are targeting at will determine which generic goals and practices are applicable. When trying to reach maturity level 2 the process areas at maturity level 2 as well as generic goal 2 and the accompanying generic practices are applicable. Generic goal 3 is only applicable when trying to reach maturity level 3 or higher. This means that when you have already achieved a maturity level 2 rating, to achieve a maturity level 3 rating you must return to maturity level 2 process areas and apply generic goal 3 and the accompanying practices. This applies to all process areas expect for the level 2 process areas Test Policy and Strategy for which a managed process suffice, and therefore generic goal 2 is not applicable.

Institutionalization is an important concept in process improvement. When mentioned in the generic goal and generic practice descriptions, institutionalization implies that the process is ingrained in the way the work is performed and there is commitment and consistency to performing the process. An institutionalized process is more likely to be retained during times of stress. When the requirements and objectives for the process change, however, the implementation of the process may also need to change to ensure that it remains active. The generic practices describe activities that address these aspects of institutionalization.

Supporting process areas for generic practices

While generic goals and generic practices are the model components that directly address the institutionalization of a process across the organization, many process areas either in TMMi or CMMI likewise address institutionalization by supporting the implementation of the generic practices. The table hereafter provides an overview of the process areas that partly of fully support the implementation of a generic practice.

Supporting CMMI process areas for TMMi

Although TMMi can be used in isolated, it is also positioned as a complementary model to the CMMI. As a result in many cases a given TMMi level needs specific support from process areas at its corresponding CMMI level or from higher CMMI levels. Process areas and practices that are elaborated within the CMMI are mostly not repeated within TMMi; they are only referenced. An overview of supporting CMMI process areas required for TMMi level 2 achievement is shown in table 2. Note that some these relationship were already identified, although from another perspective, in the previous section.

Note that the test specific process areas of the CMMI Verification and Validation are not listed as supporting process areas for the TMMi. For these CMMI process areas, the TMMi process areas provide support and a more detailed specification of what is required to establish a defined verification and validation process.