Difference Between CMMI and Six Sigma (With Table)

To bring consistency in the quality of various services and products, numerous methodologies have been adopted. Every methodology aims to improve efficiency, maintain the levels of quality, minimize errors and innovate the procedures and processes. Two common techniques used by organizational processes are CMMI and Six Sigma.

CMMI vs Six Sigma

The main difference between CMMI and Six Sigma is that CMMI is domain-specific. On the other hand, Six Sigma caters to a diverse domain range and is non-specific of any domain. The implementation of CMMI is complicated and requires time and effort while the implementation of Six Sigma is simple and easy.

CMMI is the short term to refer to Capability Maturity Model Integration. It was developed by the government of the US under the supervision of Carnegie Mellon University. CMMI is a type of model for the improvement of processes.

While the origin of the name Six Sigma is from the statistical modeling type during processes of manufacture. The introduction and development of the process were done by an American engineer known as Bill Smith. Six Sigma is a methodology for the improvement of processes. The process is extensively customer-centric.

Comparison Table Between CMMI and Six Sigma

Parameters of Comparison


Six Sigma

Wisely used Standard

De facto standard

Methodology type

Primary focus

It focuses on the improvement of the processes of products and services through maturity model

It focuses on reduction and minimization of the variability and improving the product and processes

Leadership type

Project team

Leadership availability in the green belt and black belt

Techniques and tools

Do not offer any techniques and tools

Offers advanced analytical and statistical tools


Five stages of Managed, Initial, Defined, Optimized and Quantitatively Managed

Five data-driven stages of Defining, Measuring, Analysing, Improving, and Controlling

What is CMMI?

CMMI stands for Capability Maturity Model Integration. It refers to a model which is designed for process improvement. The primary principle on which the model of CMMI operates is that the quality of a specific system, process, or product should be entirely based on the process quality that is integrated into the maintenance and development.

The CMMI method is also effective in influencing and guiding the developmental stages of the processes to meet the goals of an organization. The model is effective in increasing the performance of the organization. According to a survey of SEI, the categories like quality, cost, productivity, schedule, and even customer satisfaction have increased after CMMI.

CMMI was developed by the U.S. Government through Carnegie Mellon University. The appraisal and training program is a subsidiary of ISACA and had been administered by CMMI Institute. The registration of the process is done in US Patent and Trademark office through CMU. The model has a goal-driven approach that selects and deploys relevant processes in CMMI roadmaps from the model of CMMI- DEV.

The three main areas which are covered under the model of CMMI are service management, establishment and delivery, development of product and services, and acquisition of product and services. The model can be used across an entire organization or for a particular division or project. The maturity levels which are defined by CMMI are Managed, Initial, Defined, Optimized, and Quantitatively Managed.

What is Six Sigma?

Six Sigma refers to a set of tools and techniques which are incorporated for the improvement of various processes and organizations and businesses. The introduction of the process was by Bill Smith in the year 1986. The primary aim of the tool is to improve the quality of manufacturing through the identification and removal of the causes of such defects.

The model of Six Sigma is based on quality management methods through statistical and empirical ways. Every project of Six Sigma has a defined methodology that aims at particular value targets. The origin of the term has been from the statistical modeling type during processes of manufacture. The process can minimize the variability in the process of manufacture.

The tools and techniques provided in Six Sigma are ideal for mid-size to large organizations. The process is incorporated in domains like manufacturing, finance engineering, construction, supply chain, healthcare, and various other fields. It provides strategic objectives with enhanced prioritization and selection in the organization.

The basis of Six Sigma is on five primary data-driven stages which are known as DMIAC which stands for Defining, Measuring, Analysing, Improving, and Controlling. However, there is numerous criticism around the approaches of Six Sigma. Various quality experts state lack of originality, inadequacy for complex manufacturing, extreme reliance on statistics, and various other factors.

Main Differences Between CMMI and Six Sigma

  1. CMMI is ideal for the software and hardware industry while Six Sigma is ideal for diverse industries like construction, manufacturing, engineering, finance, healthcare supply chain, and other application.
  2. The main focus of CMMI is on process improvement while the main focus of Six Sigma is to eliminate defects in various levels and improve the process across diverse domains.
  3. The participation in CMMI is by the project team and the specific people of the particular process while the participation in Six Sigma can be by all the employees.
  4. The methodologies used in CMMI are continuous and staged representations while the methodologies used in Six Sigma are mainly DMADV and DMAIC.
  5. The limitation of CMMI is that it has a model of “how to do” and not “what to do” while the limitation of Six Sigma is that it cannot rapidly improve the speed of the process or bring a reduction in the capital investment.


Both CMMI and Six Sigma aim to add value and efficiency to the organization. The processes of an organization are improved and developed through both techniques. The goals and targets set by the organization can be completed faster with the implementation of these tools.

Both the processes cater to different types of organizations and businesses. The origin, features, and functionalities offered by both the processes are different from each other. The users need to evaluate all the points of distinction before making a final choice of decision with the process for their organization.


  1. https://books.google.com/books?hl=en&lr=lang_en&id=JNrTKCDq-mAC&oi=fnd&pg=PT13&dq=cmmi+and+six+sigma&ots=FFM8iBav-R&sig=DlU6BH5BpZuDdYfUA8oTFpNVhOQ