· 1 min read
Time Windows, Capacity, and Multi-Stop Routing Explained
A clear explanation of the three constraints that define real-world multi-stop routing: time windows, vehicle capacity and service time.
Plain multi-stop routing asks: in what order should I visit these places? Real operations add constraints that change the answer completely.
Multi-stop routing
With one vehicle, ordering stops is the traveling salesman problem. With several vehicles, you must also decide who visits what. That combined problem is the vehicle routing problem (VRP).
Vehicle capacity
Each vehicle can carry a limited load. Capacity might be counted in items, kilograms or cubic meters. A route is feasible only if the stops assigned to a vehicle fit within its capacity.
Practical implications:
- An order larger than every vehicle cannot be delivered and should be flagged early.
- Mixed fleets (small and large vans) change which stops go where.
- Balanced loads can also balance driver workload.
Time windows
A time window says "serve this stop between 9:00 and 11:00". Arriving early means waiting; arriving late breaks the promise.
Time windows turn routing into scheduling: the best geographic order may be infeasible because of timing. Tight windows can force longer routes or more vehicles.
Service time
Unloading a pallet and servicing a boiler take different amounts of time. Service time must be included, otherwise planned arrival times drift as the day goes on.
How constraints interact
Capacity limits how many stops a vehicle can take; time windows and service time limit when and how long. Together they determine whether a plan is feasible. When no feasible plan serves every stop, the honest output is a list of unassigned stops and reasons.
Seeing it in a tool
AIRO supports multi-vehicle planning with capacity, service time and time windows from a single depot, and reports unassigned stops clearly. Multi-depot and driver skills are planned for later.
Next step
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