As a professional delivery worker and an employee of the everyone-hates retailer i have this view: This is an experiment. Only. Lore has said that 75% of delivery cost is labor related. Wal-Mart is insane about not working off the clock. They won't force associates to do this. From the delivery aspect: When we get a new delivery person they suck for months. There are so many variables that make failure probable: unma…
You mention many problems.
Most of them can be solved with data gathering - what's this unmarked address, which is the relevant unit, what the right access path, which workers do and don't give a shit, etc.
and with the right app, and so many employees, you can gather all that data relatively fast, assuming some repeat orders.
Heck, maybe do that with augmented reality via phone, to make it dead simple.
Also, if the employee still can find where to go, some sort of remote help from another employee can be had.