The Restaurant Listing and Delivery Time Promise

When a customer opens the shopizona app, the first call is made to the Delivery system to figure out:

1. The restaurants are actually serviceable to the customer, which means those from which delivery is possible within some stipulated time (say, at most 30 minutes).
2. The expected delivery time of an order from a potential restaurant.

An astute reader can already see the massive challenge.

First of all, how do we find serviceable restaurants? It’s the set of those restaurants where a customer could place an order and have it delivered within the maximum delivery time.

But how can we calculate that? We roughly show 20–40 restaurants to each customer and consider thousands more. If it isn’t shown within half a second, the customer will just leave the app.

Is it feasible to find all the restaurants such that a Delivery Executive can reach there, pick up the order and deliver it to the customer? To even begin to do that, we need to calculate:

1. Assignment Delay: How long before we can find a Delivery Executive who can fulfill this order?
2. First Mile: How long before they arrive at the Restaurant?
3. Prep Time: How much time is required for the Restaurant to prepare the food?
4. Last Mile: How much time is required for the Delivery Executive to reach the customer from the Restaurant?

Combining the components above, we arrive at the Delivery Time Equation:

Delivery Time = Max (Assignment Delay + First Mile Time, Prep Time) + Last Mile Time

A quick note about the formula: Since the assignment delay and first mile happen in parallel with the restaurant’s food preparation, we take the maximum of the two times.

If we show too few, the customer will not place an order since his favourite restaurant may be unserviceable. At the same time, if we take too long to show the list of restaurants, they will leave the app.

If we show too low a delivery time and we don’t deliver within it, it leads to bad customer experience. If we show too high a delivery time, the customer may not order to begin with.

Well no, not at our scale. And here’s why.

1. Google Maps is just too slow for the number of combinations we need to calculate.
2. Google Maps is prohibitively expensive.
3. Google Maps doesn’t accurately predict travel times for people on two-wheelers (which most of our Delivery Executives use).
4. Google Maps doesn’t predict how long it will take for the Delivery Executive to go from outside the society gates to actually reaching your door and handing over the package (AKA the last last mile). While this might not make a big difference for other kinds of deliveries, an additional 5 to 10 minutes in food delivery can significantly hamper customer experience.

Thank you.