3,900 km less travelled every day
30 fewer vehicles needed for the same number of orders
Meeting narrow time windows
Including 2 different load spaces (cold and standard)
Industry: a chain of online grocery supermarkets, with delivery to the customer
Challenge: to visit all planned customers, minimizing the number of routes every day
The company specializes in home grocery delivery, ordered online via a mobile application. All products come at attractive prices and delivery is free. The customer orders 1 day in advance, can set the exact delivery time of the goods and monitor their route in the application.
By using electric vehicles the company minimizes operating costs.
Problem description
The company has more than 30 depots in a European country. Emapa analysed the delivery mode for one of them for 4 selected days of the week. Drivers visited 310, 325, 444 and 349 customers in these days, travelling 23, 24, 32 and 24 routes respectively. The average distance between the points was 10 minutes and the average stopping time at each point 6 minutes. On average, the driver visited 13 customers on 1 route, covering 130 km. The challenge for this problem are the narrow time windows, i.e. the time intervals when the customer expects his delivery (45-60 minutes) and their high density (all are in the afternoon).
The additional complication of route optimization was that 2 different loading spaces were included in vehicles – cold and standard. A typical order to the point was 1-2 standard parcels and 3-5 cold parcels.
Solution
The aim of the optimization performed by Emapa was to minimize the number of routes travelled by drivers delivering products from the selected depot each day. The proposed solution had to take into account the narrow and proximate time windows, and the different temperatures of the goods being transported (“multicapacity problem”). The solution obtained by Emapa reduced the number of routes for each day by 1, i.e. the same points were served, thus eliminating 1 of the routes. The time required by Emapa for calculations was comparable to the time when the worse solution was obtained by the company.
Each route reduction on a given day is approx. 130 kilometres saved for 1 depot, i.e. approx. 20 kWh. Since the company uses electric vehicles, the energy costs saved are not crucial here. The charging time for each subsequent car is important. The company may therefore give up one vehicle in a branch (depot) with a value of at least PLN 140,000 or a leasing instalment of PLN 3,000 per month. Giving up 1 vehicle also means cost savings in paying the driver, which in the country – headquarters of the supermarket chain, amount to approximately PLN 12,000 per month. With over 30 depots used by the company every day, the savings amount to several hundred thousand PLN per month.