The Influence of Lean Six-Sigma Tools in Reducing the Cost of Quality and Fulfilling of Competitive Advantage of Firms. Psychosocial rehabilitation [Internet]. 2020 Jan. 30 [cited 2024 Dec. 28];24(3):521-4. Available from: http://65.2.176.223/psychosocial/index.php/ijpr/article/view/1827