Milk run

A milk run is an inbound pickup route in which one vehicle follows a fixed, pre-selected loop, collecting parts from several suppliers and delivering the combined load to the plant, instead of each supplier delivering separately. It trades many small direct deliveries for one consolidated trip on a timetable synchronised with the suppliers.

Milk run or direct delivery

In a case published in Management and Production Engineering Review in 2019, Astra Daihatsu Motor's milk run in Indonesia grew from 50 trips a day in 2008 to 200 in 2017, serving two plants with 12-tonne, 12-metre trucks; the authors credit consolidated transport with cutting transport cost even with small lots, and with making the delivery cost per part visible. A 2024 study in Scientific Reports found a cyclic pickup method cut total distance by 26.67% and waiting time by 46.60% against a traditional milk run. Inside a plant the same name means delivering materials to assembly lines in small, frequent lots.

Worked example: five suppliers

The mistake people make

Running the loop with no slack for traffic. Every supplier's parts ride the same truck, so one delay hits the whole loop: the 2019 study warns that late arrivals caused by traffic jams can stop the production line. Build a buffer into the pickup windows and track the truck against them.