After being made redundant; for six months I worked as a parcels courier for Interlink (A franchise operation).
Obviously, companies will vary, (as will each Depot and courier) in their efficiency and conscientiousness. Lack of care could result in damage to a consignment, at any stage of the process.
Everyday was a stressful 13 hour one, very often needing to be somewhere else 5 minutes ago, for a desperately urgent collection. Sometimes, the address was anything but clear, or obviously marked.
If a parcel was delivered a day late, it was only because an error by one of the couriers. Every item was scanned onto the vehicle, and off, with a handheld scanner, (PLUS a receipt signature) the results being downloaded at days end to confirm delivery.
Some deliveries were "timed", and theoretically had to be delivered by 0900. Try that when you have three, for destinations in places each some 15 -20 miles form the others! But barring the odd acceident, everything got there the same day as it arrived at the depot. The worst problem was folk who did not know the difference between Bourn in Cambridgeshire and Bourne in Lincolnshire, and then complained of delivery a day late!
Howard