The Test Maturity Model Integrated (TMMi)

The Testing Maturity Model (TMM) was based on the Capability Maturity Model, and first produced by the Illinois Institute of Technology.

Its aim to be used in a similar way to CMM, that is to provide a framework for assessing the maturity of the test processes in an organisation, and so providing targets on improving maturity.

There are five levels of maturity as follows:
Level 1 – Initial At this level an organisation is using ad-hoc methods for testing, so results are not repeatable and there is no quality standard.
Level 2 – Definition At this level testing is defined a process, so there might be test strategies, test plans, test cases, based on requirements. Testing does not start until products are completed, so the aim of testing is to compare products against requirements.
Level 3 – Integration At this level testing is integrated into a software life cycle, e.g. the V-model. The need for testing is based on risk management, and the testing is carried out with some independence from the development area.
Level 4 – Management and measurement At this level testing activities take place at all stages of the life cycle, including reviews of requirements and designs. Quality criteria are agreed for all products of an organization (internal and external).
Level 5 – Optimization At this level the testing process itself is tested and improved at each iteration. This is typically achieved with tool support, and also introduces aims such as defect prevention through the life cycle, rather than defect detection (zero defects).

It provides a structured presentation of maturity levels, allowing for standard TMMi assessments and certification, enabling a consistent deployment of the standards and the collection of industry metrics. 

TMMi has a rapidly growing uptake across Europe, Asia and the USA and owes its popularity to being the only independent test process measurement method.

Source :  Wikipedia