This article will shortly introduce to the topics of Capability Maturity Model Integration (CMMI) and Six Sigma. By comparing these two project management approaches and analysing dependencies between them, a quick multilateral examination can be given. Firstly, two short introductions should basically describe CMMI and Six Sigma. Then similarities and differences are sorted out. In the end, a conclusion merges all results from the investigation.
CMMI is “a framework for managing processes and integrating activities across an organisation.” It delivers a set of best-practices for improving processes in an enterprise. CMMI can integrate traditionally separated activities through divisions and departments. Six Sigma is “a problem solving approach that addresses specific improvement needs through improvement projects”. Six Sigma was firstly developed for the production industry. The approach shall reduce defects and shift process quality up to a reliable level. A sigma function is used to measure meanderings. (cf. http://www.sei.cmu.edu/library/assets/banerjee08.pdf p.7).
Business challenges often address three main fields like time, productivity and defects. Therefore, process improvement methods help to avoid quality defects and raise the level of reliability. Both approaches are developed for adding value to the company processes. Besides, there are three main practices, which are found in both CMMI and Six Sigma. The first one is, that both approaches are orientated in figuring out key stakeholder in the early stage. Additionally, monitoring and control are main factors. Collecting data according to improvement of the processes can help to identify good patterns, which are responsible for adequate process output (cf. http://www.sei.cmu.edu/library/assets/wilson-sixsigma.pdf p.6).
Six Sigma is defined by phases whereas CMMI includes process areas. Each of the process area has an acronym, which can be found here: http://www.tutorialspoint.com/cmmi/cmmi-process-areas.htm .Through a scheme, a person of responsibility can match the structure of improvement processes related to CMMI with processes defined by Six Sigma. A structure similar to the scheme described is given in the table below. A merge of the field of both concepts can help to improve processes and reach a level of high conformity.
|Define||PP(L2) REQM(L2) RD(L3) OPD(L3) IPM(L3)|
|Analyse||REQM(L2) DAR(L3) QPM(L4) OPP(L4) CAR(L5)|
|Improve||OT(L3) OPF(L3) OID(L5)|
|Control||PMC(L2) IPM(L3) QPM (L4)|
Although the part above is showing that CMMI and Six Sigma can be applicated together, there are some differences, that a person of responsibility must keep in mind. One the one hand, Six Sigma uses statistical methods for measuring process conformity. CMMI has mathematical party but they are often classified as unnecessary and rarely used. Six Sigma uses rather internal experiences than external tests. CMMI has a mechanism for integration of external technology. Moreover, Six Sigma support soft skill training as well as general communication skills. CMMI addresses more the infrastructure behind a company´s processes. At least, Six Sigma provides a categorization of individual persons. In contrast, CMMI provides a certification in terms of leveling organisations (cf. https://www.slideshare.net/Hari772003/differences-between-six-sigma-and-cmmi)
All in all, Six Sigma and CMMI can work together in an organisation. Many aspects can be related to each other. Sophisticated measurement is the key success factor for the co-existence of both concepts. Nevertheless, Six Sigma is more business orientated. CMMI in general enhances the improvement activity of processes.