Four cases of water.
One third-floor door.
The map stops at an address. The carrying may only be starting.
Same subtotal, different lifting
Item cost does not measure weight, volume or carrying trips. Water, pet food and bulky household goods can turn a short distance into a demanding handoff. This is a workload explanation, not a claim that every heavy order pays the same.
Customer POV: this is why I need delivery.
Heavy items and stairs can be exactly why someone orders. Disability, illness, limited transportation and caregiving can make a grocery trip difficult. Customers deserve respectful service and should not have to disclose personal circumstances to be treated decently.
Driver POV: the trip has several parts.
Parking, finding the entrance, using an elevator, passing a gate and making multiple carrying trips can add minutes after arrival. The vehicle is not the only resource in use. The driver is doing physical work too.
Good directions are a real contribution.
Add accurate unit and building details, relevant entry instructions and a safe drop-off location. Keep pets secure and paths clear where possible. Share only access information necessary for delivery. Timely answers can reduce unnecessary searching.
How to model this
Add realistic handoff minutes in the calculator rather than assuming a map arrival ends the job. Increase waiting only for actual waiting; do not count the same time twice. A tip is one contribution to the offer, not a guarantee that every service request is permitted or physically possible.
Independent educational guidance. Examples are illustrative. Sources and assumptions ↗