Al-Hamdani, A.M.S. and Mohammed, A.M. 2024. Requirements Applying of Six Sigma Methodology to Reduce Productive Wastage at Yemeni Pharmaceutical Manufacturing Companies: A Field Study . Journal of Social Studies. 30, 1 (Mar. 2024), 30–59. DOI:https://doi.org/10.20428/jss.v30i1.2337.