This paper presents an analysis of the economic performance and profitability of companies using the Six Sigma methodology. Of the 425 Brazilian companies currently on the open market, 93 use Six Sigma. The companies were first categorised by their sectors, according to how they are classified on the capital market, and then, by their size according to the Brazilian Development Bank. The results in recent years (2011–2013) of companies that use Six Sigma were compared to the results of those

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... t do not, based on a statistical inference test of the differences between the two populations, with unknown standard deviations and a confidence interval established at the 95% level. The findings show that, in nine sectors, the Six Sigma methodology contributes to the optimisation of processes and economic performance.