Capability Maturity Model Integration (CMMI) is the synthesis and improvement of several process models. Continuous model and stage model are two representations provided by CMMI, and continuous model includes six process domain capability levels.

CL0 (Incomplete): The process domain did not execute or did not get all the targets defined in CL 1.

CL 1 (executed): Its * * * goal is that the process transforms the identifiable input work product into the identifiable output work product, so as to achieve the specific goal of supporting the process domain.

CL2 (managed): Its goal is to pay attention to the institutionalization of management process. According to the organization-level strategy, which process will be used for the operation of the process, the project follows the documented plan and process description, all staff have the right to use sufficient resources, and all work tasks and work products are monitored, controlled and reviewed.

CL3 (Definition Level): Its * * * goal focuses on the institutionalization of the definition process. The process is cut from the organization's standard process according to the organization's cutting guidelines, and process assets and process metrics must be collected and used to improve the process in the future.

CL4 (Quantitative Management): Its * * * goal focuses on the institutionalization of processes that can be managed quantitatively. Use measurement and quality assurance to control and improve the process area, and establish and use quality and quality objectives of process implementation as management standards.

CL5 (Optimization): Change and optimize the process domain by quantitative (statistical) means to meet the customer changes and the efficacy of the process domain in the continuous improvement plan.