PLN 8,000 in savings per month on vehicles in 2 depots
elimination of drivers’ working hour overruns
25% fewer routes to serve selected points
planning time reduced by 90%
Industry: tyre sales and service
Challenge: reduction of kilometres when organizing work in 2 modes: maximum filling of vehicles (in season) and work for all drivers (out of season)
The company sells and provides comprehensive service for tyres and wheels for all types of vehicles. In addition, it provides air conditioning services and other mechanical services. A 24-hour mobile service is available for servicing truck and agricultural tyres.
Problem description:
The company has several depots, from which vehicles with a weight of 3.5 tons and a capacity of 12 m3 leave every day. Customers served by the service work mainly from 08:00-16:00 pm and have to be visited by salesmen/service technicians during this time. The company would like to calculate optimal routes (reducing kilometres) in 2 modes:
- In season: a large amount of goods to be delivered, which must fit on the available vehicles, using their load space to the maximum
- Off season: much fewer goods to be delivered, where each driver should have a job
The number of drivers and routes changes every day. Some customers, however, have to be firmly assigned to a specific route. Additionally, the company would like to know, when planning seasonal deliveries of tyres and parts, how many of them can be served using their own fleet, and how many should be outsourced to a courier company. Planning a route schedule is now a long and laborious process and takes several hours.
Solution
2 depots were analysed, from which a total of 263 points were served. The average service time at the point was 5 minutes. Currently, the company served these points using 12 routes, 6 from each depot. The total length of the routes was optimal (approx. 3,400 km), but the total working time of the drivers overrun by 9 hours. After optimization of the analysed case, the company received 6 different solution variants. In the variant minimizing the number of routes, the same points were served by 9 routes with a total length of 3,013 km. However, the drivers could work then up to 2 hours longer than normal. Another variant assumed that all 6 drivers leave each depot and 12 routes had a total of 3840 km. None of the drivers then exceeded their 8-hour working time.
After a few minutes of optimizer’s work, the company has 6 different route variants, from which it can freely choose the ones that are most profitable in a given situation (peak season or off season). In a version that minimizes the number of routes (i.e. vehicles and drivers), they have been reduced from 12 to 9 on a scale of 2 depots. With this option, the company will eventually give up 3 vehicles in these depots, which generates about PLN 8,000 in savings per month (leasing, driver, fuel costs).