Sizing a station looks like an arithmetic problem: expected parcels divided by compartments. It is not, because compartments are not interchangeable and parcels do not arrive evenly. A station can sit at half occupancy and still refuse deposits every evening if the mix is wrong.
Mix before count
Parcel profiles differ by catchment. A residential compound sees small ecommerce items with a heavy evening peak. A retail site sees larger click-and-collect orders staged in batches. A workplace sees documents and returns. The distribution of compartment sizes should follow the observed profile of the site, and it should be revisited once the site has run long enough to have one.
- Size the mix from measured parcel dimensions, not catalogue defaults.
- Keep a reserve of larger compartments; an oversized parcel with nowhere to go fails the whole deposit.
- Watch refusals by size, which reveal mix problems occupancy hides.
- Re-cut the mix after the site’s first full seasonal cycle.
Turnover is the real capacity
A compartment that cycles twice a day carries twice the volume of one that cycles daily, with no extra steel. That makes collection speed a capacity lever: notification timing, dwell limits and expiry handling change how much a station can carry more cheaply than adding hardware does.
Peaks decide the specification
Averages flatter an estate. Sizing should be against the peak hours the site actually experiences, with a deliberate decision about what happens when that peak is exceeded: overflow to a neighboring station, a held deposit, or a refused one. Choosing that behavior in advance is planning; discovering it during a peak is an incident.