A process improvement framework such as Capability Maturity Model (CMM) can help develop the maturity of a software development organization over time to achieve predictable and repeatable process performance. However, in the absence of a methodology for process performance measurement, ongoing data-oriented process improvement is hard to institutionalize. For organizations following CMMI, this makes navigating their way through higher-level process management and optimization activities called forth in CMMI Level 4 and Level 5 especially challenging. Altogether, this constitutes a major stumbling block for software organizations striving for higher process maturity as Level 4 and Level 5 Process Areas are essential to institutionalizing process improvement in an organization.

Six-Sigma introduces tremendous process measurability through its statistical error-control focus and offers compelling tools and techniques that have strong applicability to software development. Six-Sigma focus on data and metrics married with the CMMI coverage of all aspects of software development through its Process Areas can together provide a powerful process control and improvement framework.

A CMMI and Six-Sigma hybrid framework has been presented as a means of achieving software development performance and productivity improvements through statistical error control. Such a hybrid CMMI and Six Sigma framework provides not just greater guidance and rigor in certain areas than CMMI alone but also an inherent flexibility by making an extensive toolset available for use in a wide variety of scenarios. This integrated framework demonstrates that CMMI and Six Sigma are highly complementary and are capable of adding greater value when used in conjunction with each other. This is partly because together they address the weaknesses that may become apparent when either framework is used alone. Six Sigma answers the 'how' for areas where CMMI only provides the 'what'. Conversely, CMMI provides the overall vision and roadmap that is lacking from individual Six Sigma improvements. It is hoped that this will serve as a blueprint for an implementation of CMMI that makes use of relevant Six Sigma tools and techniques.

Library of Congress Subject Headings

Computer software--Quality control; Capability maturity model (Computer software); Six sigma (Quality control standard); Software engineering

Publication Date


Document Type



Steve Zilora

Advisor/Committee Member

Larry Hill

Advisor/Committee Member

Deborah Coleman


Physical copy available from RIT's Wallace Library at QA76.76.Q35 M34 2005


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