Ship to Home - Verification and Validation

When shipping perishable food items via FedEx etc, what is the best business practice for verification and validation of this process since there are sooo many variables outside of our control (ambient air temp, sitting outside on someone's porch, transit delays). Any help is appreciated. 

The short answer is you cannot

You'd have to validate every possible scenario individually

Shipping perishables via courier that is NOT a direct warehouse to customer vehicle is playing russian roulette with your finished goods

I used to work at a meal kit company, and we delivered perishable ingredients (proteins, cut veg, sauces, etc) in a reusable insulated cooler with ice packs. There was a proprietary algorithm that used the temperature at the production facility and the temperature at the consumer's home plus the distance to the consumer's home to determine how much ice would needed to keep everything in the appropriate temperature range. In the end, we ended up packing as many ice packs as could fit, and only accepting orders from customers that lived within a 2 day shipping range, because we couldn't guarantee the temperature after 2 days.

I wasn't part of the team that did the original testing, but they packaged up a variety of items as they would be delivered to the consumer and shipped them to partners at various distances from the production facility, then took temperatures of the ingredients to see if they were appropriately cooled. In the absence of partners to ship them to, you could leave the final product in various places (trunk of a car, office, somebody's front porch, etc) and then take temperatures at 24, 48, etc hours to see how long the food stays cool in "real world" conditions.

Obviously, the packaging is going to dictate how long the food will stay safe. Our consumers returned the insulated coolers to us for cleaning and re-use, but that was expensive and time-consuming.