Why do vending machine routes keep slipping behind schedule?

What to take away

The three constraints, in order

Route scheduling fails when it is treated as a distance problem. Distance is real but it is rarely the binding constraint.

Access windows bind first. A plant that admits you at shift change, an office that is empty after five, a school with visitor hours, a hospital floor with escort requirements: each is a fixed appointment, and the flexible sites have to fit around them.

Vehicle capacity binds second. If the load for a full round does not fit, the day contains a return to storage, and that leg has to be in the plan rather than discovered at two in the afternoon.

Drive time binds third. It is the one everybody plans for and the easiest to measure once you stop trusting estimates.

Measure the legs you actually drive

Map estimates are made for an empty road. Time each leg of your route yourself, in the hour you normally drive it, and record it. Two weeks of that gives you a table you can schedule from.

Record three numbers per site, not one: drive time to it, time inside from parking to leaving, and any wait before you can get in. The third is invisible on a map and it is where routes lose their afternoons. A site with a ten minute drive and a twenty minute wait at reception is a thirty minute site.

Anchor, then fill

Build the day in that order.

The last point separates a schedule that survives from one that looks efficient on paper. A plan with no gaps only works when nothing goes wrong.

Intervals do not have to match

Forcing every machine onto a weekly rhythm is a habit rather than a decision, and it produces two kinds of waste: visits to machines that did not need one, and sell outs at machines that needed two.

Set the interval per machine from its busiest selection. If a column holds c units and the fastest selection sells U units per day, that machine can go roughly c divided by U days before it runs dry, less a buffer for variation. Then group machines whose intervals are compatible into days that make geographic sense.

Telemetry makes this much easier, because it tells you what sold without a visit and lets you skip a machine that does not need one. The par levels behind those intervals are what make skipping safe.

Where delays actually come from

Track the reasons for a fortnight and the list is usually short.

Each has a different fix, and only one of them is about driving. Reception waits are solved by an arrangement with the site contact, not by leaving earlier. Faults are solved by carrying the parts that fix the common ones. The stock problem is solved by better pars, which is a data problem rather than a scheduling one.

Building slack in on purpose

Slack feels like waste until the first time a machine fails at eleven in the morning.

Plan each day to a share of your available driving hours, not all of them. Keep one or two flexible sites that can be dropped to the next day without consequence. Name those sites in advance.

Choosing which stop to sacrifice while running late gives the wrong answer. The easiest site to skip is often the one that most needs the visit.

Where a site is repeatedly the cause of delay, that is a conversation with the host rather than a scheduling adjustment. Access arrangements are usually negotiable, and a manager who knows the driver waits twenty minutes every week will often fix it.

Seasonal and shift changes

Routes decay quietly because the sites change and the schedule does not.

Term time ends at a college. A plant adds a night shift. An office moves to three days in the building. Each of those changes demand and sometimes changes access, and none of them announce themselves in a route plan.

Ask your site contacts about the coming quarter rather than waiting for the sales to tell you. Then rebuild the affected days. A schedule reviewed quarterly stays roughly right; one reviewed annually is wrong for most of the year, particularly if you have taken machines into a new area where the local pattern is unfamiliar.

What to record on every run

Keep it short enough that it actually gets filled in.

That last one is both an operational and a record keeping matter, since sales and receipts are part of what the Internal Revenue Service: What kind of records should I keep? guidance expects a business to hold. The rest of the visit sequence belongs to the operations framework, which sets out what happens at the machine itself.

Two checks belong in the run regardless of time pressure. Confirm the approach to the machine is clear, since machines in a place of public accommodation are subject to the requirements in the U.S. Department of Justice: 2010 ADA Standards for Accessible Design.

Also record temperatures on refrigerated machines in whatever form your health department expects. The U.S. Food and Drug Administration: State Retail and Food Service Codes and Regulations directory identifies the agency whose answer applies, and the licensing position you hold should already say what that is.

When the route is genuinely too long

Sometimes the schedule is not fixable because the route has outgrown the day. Three responses, in increasing order of commitment.

Lengthen intervals where pars allow it. Drop the machines that fail their own visit test, usually a small number of distant sites.

Or add a driver, turning a scheduling problem into a hiring and cost problem you can model before committing. If you are still building the first route, refusing distant sites early is the cheapest insurance against all three.

Common questions

Should I use route optimization software?

It helps once the route is large enough that the ordering is not obvious, and it is only as good as the times you feed it. Software using map estimates rather than your measured site times will produce a confident and unachievable plan.

Is it better to service in the morning or the afternoon?

Follow the site rather than a preference. Machines should be full before the building's peak, which means before a shift starts or before lunch. A route that reaches its busiest site at four in the afternoon is servicing after the sales it was meant to support.

How do I handle a site that always makes me wait?

Ask the contact for a workable arrangement: a key, a code, a named person, or a standing time. Most waits exist because nobody was asked to remove them. If it cannot be fixed, price the wait into the site's service cost and decide whether the machine still clears it.