“QUALITY ANALYSIS OF GOODS DELIVERY SERVICE USING SIX SIGMA APPROACH IN PT. KAMADJAJA LOGISTICS SURABAYA”. Tibuana : Journal of Applied Industrial Engineering 3, no. 02 (July 29, 2020): 58–71. Accessed June 4, 2026. https://jurnal.unipasby.ac.id/tibuana/article/view/2565.