Efficient spare parts delivery model promises cost and emission reductions

A distribution model designed to streamline spare parts delivery to roadside assistance vehicles could cut costs in half, according to work published in the International Journal of Shipping and Transport Logistics.

The model builds a solution to the well-known Traveling Salesman Problem, a complex optimization problem that involves finding the shortest route that visits each city once and ends at the starting point. The model was tested on real data from a roadside assistance company operating a fleet of service vehicles.

Abolfazl Shafaei, Mohammad Reza Akbari Jokar, and Majid Rafiee of Sharif University of Technology in Tehran, Iran, and Ahmad Hemmati of the University of Bergen in Bergen, Norway, explain that the major logistical challenge for roadside assistance fleets is balancing inventory space with repair capabilities.

Service vehicles have limited space onboard, so they must prioritize particular spare parts and specific tools. Service vehicles usually visit a central warehouse on a regular schedule to restock on spare parts every few days. This adds to overall fuel costs, vehicle wear and tear, and lost servicing time.

The new system replaces these frequent trips with a centralized delivery truck that optimizes the frequency and route of spare part deliveries.

However, drivers everywhere expect fast, efficient service from the company with which they entrust their vehicle’s roadside maintenance. They also expect it to be inexpensive and a high-quality service.

The team tested several delivery schedules, including daily and every five days, and found that the most efficient option for this roadside assistance company was an optimized cycle on the first, second, and fourth days. This approach reduced costs by 56%.

The new model reduces the need to stockpile items by ensuring regular deliveries to the service fleet out on the road. This frees up space for repair equipment that allows for a wider variety of roadside fixes.

Beyond the immediate time and cost savings to companies running roadside assistance fleets, the model also promises significant environmental benefits. With fewer vehicles returning to a central warehouse to restock, fuel consumption and carbon emissions can be greatly reduced. Indeed, for the test case, the team found that annual carbon dioxide emissions could be reduced by 75%.