Six Sigma as a path breaking  methodology for the business improvement has its own advantages and disadvantages.

Advantages :

(1)   Six Sigma is driven by the customer and thus aims to achieve maximum customer satisfaction and minimizing the defects. It targets the customer delight and new innovative ways to exceed the customer expectations.

(2)   Implementation of Six Sigma methodology leads to rise of profitability and reduction in costs. Thus improvements achieved are directly related to financial results.

(3)   Six Sigma is successfully implemented in virtually every business category including return on sales, return on investment, employment growth and stock value growth.

(4)   Six Sigma targets Variation in the processes and focuses on the process improvement rather than final outcome.

(5)   Six Sigma is prospective methodology as compared to other quality programs as it focuses on prevention on defects rather than fixing it.

(6)   It is attentive to the entire business processes and training is integral to the management system where the top down approach ensures that every good thing is capitalized and every bad thing is quickly removed.

Disadvantages

(1)   Applicability of Six Sigma is being argued among the Six Sigma critics. They opined that the quality standards should be according to specific task and measuring 3.4 defects per million as standard leads to more time spent in areas which are less profitable.

(2)   Six Sigma gives emphasis on the rigidity of the process which basically contradicts the innovation and kills the creativity. The innovative approach implies deviations in production, the redundancy, the unusual solutions, insufficient study which are opposite to Six Sigma principles.

(3)   People argue that Six Sigma is a bit gimmicky and simply a rebranding of the continues improvement techniques and tools as practiced by Toyota. It thus promotes outsourcing of improvement projects with lack of accountability.

(4)   Six Sigma implementation constantly require skilled man force. Thus control and employee dedication are hard to accomplish if its not implemented regularly.

(5)    While converting the theoretical concepts into practical applications there are lot to real time barriers which needs to be resolved.