What is a milk run?

A milk run is fixed-route, fixed-time conveyance: one material handler — usually on a tugger pulling carts, sometimes walking with a cart — drives the same loop of stops at the same times, every interval, all shift. The name comes from the old dairy round: the same streets, the same doorsteps, full bottles dropped and empties collected in one pass. In a plant, the runner starts at a central market (a controlled parts store), loads the carts to the pull signals collected on the previous run, drives the loop delivering small quantities to point-of-use at each cell, picks up empty containers and new pull signals, and returns to the market to load the next run.

The delivery quantity varies run to run — the runner delivers only what the pull signals call for — but the route and the timing never do. That fixed interval, variable quantity pattern is what couples the route to consumption: each cell’s kanban loop is sized in multiples of the delivery interval, so material arrives in step with what production actually used.

Why timed routes beat forklifts on demand

The default in most plants is the opposite: forklifts dispatched whenever someone calls, moving full pallets to wherever there is floor space. It feels responsive, but it delivers big loads at unpredictable times — cells sit on hours of inventory yet still run short, operators leave their stations to hunt parts, and every shortage becomes an expedite. A timed route replaces all of that with a bus schedule. Deliveries are small and frequent, so lineside inventory shrinks to a couple of intervals’ worth. Deliveries are predictable, so a missing part is visible within one interval instead of at the end of the shift. And because one runner serves many cells on one loop, the plant usually moves more material with fewer people and gets forklifts — expensive, dangerous, and pallet-bound — off the production floor.

How to time a milk run route

A route is timed the same way any standardized work is timed: element by element, from observation. Set a standard time for each stop — dismount, place full containers on the point-of-use rack, collect empties and pull signals, remount — and a travel time for each leg, derived from the distance at your vehicle’s speed. Add the loading time at the market, and the total is the route cycle time, which must fit inside the delivery interval: 52 minutes of work on a 60-minute route is 87% utilization, which is a healthy, honest route. Two rules of thumb keep the shape right: loading at the market should take no more than about a third of the interval, and travel no more than about a third of the remaining on-route time.

If the cycle exceeds the interval, the route is overburdened, and rushing the runner is not a countermeasure. Split the loop into two routes, shorten stop work with better parts presentation, or lengthen the interval and carry more per run. If the cycle is far below the interval, the runner is underloaded — add stops until the route earns most of its interval. This tool does the arithmetic transparently and flags both conditions as you type.

Standard work for the material handler

A milk run only works if it is treated as standardized work, not a suggestion. The runner departs on time every interval, follows the same stop sequence, handles containers the same way at every stop, and takes breaks with the cells being served. The route sheet — stops, work at each stop, standard times, and the timeline — is posted at the market and carried on the vehicle, so anyone can see within a minute whether the route is on schedule and where the runner should be. Deviations are information: a stop that regularly runs over its standard time, or aisles blocked along the loop, are problems to solve, not conditions to absorb. That is why the printout this tool produces is a route standard work sheet, not just a map.

How to use this tool

Click Load Example to see an 8-stop tugger route feeding four assembly cells from a central market on a 60-minute interval, then edit it — or clear and start from your own route. Set the interval, cart capacity, and shift time; add a row per stop with the work performed, containers delivered, stop time, and travel to the next stop. The timeline stacks loading, travel, and stop work against the interval as a hard line, and the loop diagram shows the stop sequence from the market. When the route fits, use Download Printout for the standard work sheet, or grab the Excel template to work offline.

Related tools

• Plan for Every Part (PFEP) — the part-by-part database that tells the route what to carry, in which container, to which address
• Kanban Card Calculator — size the pull-signal loops the route replenishes
• Spaghetti Diagram— map today’s material-handling walking paths before you fix the route
• Standardized Work Combination Table — the same time-against-takt discipline, applied to an operator’s cycle