Fikri, Ali Zian, et al. “Implementation of Objective Matrix and Root Cause Analysis for Productivity Analysis PT. Indomarco Adi Prima SP Deket Lamongan”. IJIEM - Indonesian Journal of Industrial Engineering and Management, vol. 4, no. 3, Dec. 2023, pp. 597-08, doi:10.22441/ijiem.v4i3.21715.