Refill Planning for Unmanned Coffee Machines at Transit Sites
In one line: Size the refill cycle from daily cups per canister, not from calendar days — and land the refill before the peak, not during it.
Key facts: cups per canister ｜ cycle = canister capacity ÷ daily draw ｜ refill before the peak ｜ merge sites into one route ｜ two-week rolling stock buffer
Why refill timing decides throughput, not machine speed
At a station or airport, the machine is usually capable of more cups per hour than the site will ever ask of it. What actually stops throughput is a canister running empty in the middle of a peak window — and that is a planning problem, not an equipment problem.
Peak windows at transit sites are short: often sixty to ninety minutes in the morning, a flat period through midday, and a smaller second peak in the evening. A refill that lands inside the morning window does more damage than the same refill done an hour earlier or later.
Start from cups per canister, not from days
The first number to establish is how many cups one full canister delivers for each drink on the menu. That figure comes from the dose per cup and the canister size, and it differs by drink — a milk-based option usually runs out well before a black coffee option.
Divide that by the site's daily draw for the same drink and you get a cycle in days. Round down, never up: a canister rated at 4.4 days should be refilled on day 4, because the draw is an average and the last day is where the variance shows up.
| Input | Where it comes from | Why it matters |
|---|---|---|
| Cups per canister | Dose per cup × canister size | Sets the ceiling for the cycle |
| Daily draw per drink | Machine back office, by drink | Converts capacity into days |
| Peak window length | Site observation, two weeks | Decides when the refill may land |
| Route time between sites | Actual drive and access time | Sets how many sites fit one run |
Place the refill before the peak
The practical rule is to finish the refill at least thirty minutes before the peak starts, then confirm the canister levels on the machine screen before leaving. This gives a margin if the day runs busier than expected, and it keeps the service area clear when customers arrive.
Where a site has no clear trough, split the visit: top up the two fastest-moving canisters before the first peak and complete the rest at closing. Two short visits are easier to hold to than one long one, and they reduce the chance of a full stop during trading hours.
Merge sites into one route, but protect the tightest one
Refill cost is dominated by travel, so sites are usually grouped into a route. The risk in grouping is that the site with the shortest cycle gets pushed to the end of the run — it should be first, and the others scheduled around it.
A workable pattern is to fix the tightest site's refill day, then fill the remaining route slots with sites whose cycles are longer. If a site cannot be reached on its required day, the fallback is a partial top-up of the fastest-moving canister rather than a skipped visit.
Keep the route stable for at least a month. Changing the order every week makes it impossible to tell whether a stock-out came from the plan or from the day.
Hold a two-week buffer, and count it monthly
Consumables are cheap relative to a failed visit, so a two-week rolling buffer at the depot is a reasonable default. It covers a missed delivery, a busier-than-usual week, and the gap between ordering and arrival.
Count the buffer monthly against actual usage rather than against the order record. Usage drifts with menu changes and seasonality, and a buffer that is only checked on paper tends to be smaller than assumed.
One more point on record keeping: log the refill as levels before and after, not as a tick box. Levels show whether the cycle is correctly sized; a tick box only shows that someone visited.
Common questions
How often does an unmanned coffee machine need refilling?
Size it from cups per canister divided by the site's daily draw for that drink, then round down. A canister rated at 4.4 days should be refilled on day 4.
Is it better to refill during or between peaks?
Between peaks, finishing at least thirty minutes before the peak starts. A refill inside a sixty to ninety minute peak window costs sales that the same visit would not cost an hour earlier.
How many sites can one route cover?
It depends on drive and access time between sites. Fix the tightest site's refill day first, then fill the remaining slots with sites on longer cycles.
What buffer stock should be held at the depot?
A two-week rolling buffer is a reasonable default. Count it monthly against actual usage rather than against the order record, because usage drifts with menu and season changes.
What should the refill log record?
Levels before and after each refill, not a tick box. Levels show whether the cycle is correctly sized; a tick box only shows that someone visited.
Summary
Send the site type and the daily cup volume, and we will size a refill cycle and a route pattern for your locations.
Browse the machine series on the product page, or send the site details through the contact form and we will reply with a refill planning sheet.