Resumen: Product customization is becoming a competitiveness factor in most markets. It implies manufacturing small and varied batches in mixed-product assembly lines and frequently supplying parts to production lines in small quantities with high efficiency. The in-plant milk-run is a specific tool used in this context. This paper proposes an industry-validated design method for human-driven milk-runs, based on improving surface productivity. A mathematical model is defined for relating mizusumashi work time to the milk-run period and finding its minimum value. This research is particularly useful in factories with high cost per m2 supplying high-volume parts. Idioma: Inglés DOI: 10.1016/j.cirp.2020.03.012 Año: 2020 Publicado en: CIRP Annals 69, 1 (2020), 405-408 ISSN: 0007-8506 Factor impacto JCR: 3.916 (2020) Categ. JCR: ENGINEERING, MANUFACTURING rank: 19 / 50 = 0.38 (2020) - Q2 - T2 Categ. JCR: ENGINEERING, INDUSTRIAL rank: 20 / 49 = 0.408 (2020) - Q2 - T2 Factor impacto SCIMAGO: 2.37 - Mechanical Engineering (Q1) - Industrial and Manufacturing Engineering (Q1)