In more heavily globalizing world economy, Efficiency plays a crucial role in terms of sustaining countries' economic development. For the past decade, Six sigma, for which many world-wide leading corporations apply, has helped increase their profit and expand by making their all processes (e.g. manufacturing, personnel management, finance, marketing) more efficient. Six sigma, however, focuses on quality instead of speed. Lean production offsets the underlying difficulty due to slow processes. Lean management is especially known to be good at any process's flow and speed rather than quality improvement. Thus, the most desirable results can be attained when Lean management and Six Sigma techniques are used together and in a manner that both support each other. This study surveys the literature about Six sigma and Lean six sigma methodology. Studies in the literature are classified into different categories and brief information is given.