Optimizing logistics: efficient route planning despite complex restrictions
Logistics is a complex interplay of many processes and steps, ranging from ordering to delivery and beyond. Route planning in particular plays a central role here and represents one of the biggest challenges.
Have you found that your routes are not optimally planned because your vehicles are underutilized or service level agreements (SLAs) cannot be met? Or maybe there are too many options and you want to find out which one is the best, taking all constraints into account? We understand that optimal route planning is challenging. Predefined conditions and restrictions must be taken into account, as these have a significant influence on the transportation, storage and delivery processes. Despite the complexity and potential risks, it is essential to ensure efficient route planning in order to guarantee a smooth process.
What restrictions can there be?
Capacity restrictions
- Availability of vans
- Availability of drivers
- Transporter capacities (loading meters, volume, weight)
Time restrictions
- Several possible time intervals for loading and unloading shipments
- Maximum circulation time
- Driving time and rest break: consideration of driving and rest periods to comply with legal requirements
Other general conditions
- Special requirements for the transporter, e.g: Cooling, transportation of hazardous goods, lifting platforms
- Certain goods require special transportation conditions
- Possibility of fixed or preferred driver and vehicle assignments
Optimization approaches
Design heuristics
Design heuristics can be used in route planning to find practical and fast solutions. This method makes it possible to construct an initial solution by assigning shipments to transporters one after the other in compliance with all restrictions.
- Capacity restrictions: Ensure that the vehicle is not overloaded before a new stop.
- Time restrictions: Check compliance with the time windows for loading and delivery.
- General conditions: Only vehicles with suitable requirements are considered.
In this way, the optimum sequence of stops can be determined in order to approach customers efficiently.
Improvement heuristic
Improvement heuristics are used to further optimize existing solutions. An initial solution created by a construction heuristic often serves as the starting point. This is improved step by step, whereby non-valid solutions can be created in between in order to overcome local minima. As soon as a new valid solution is available, its costs are compared with the best solution to date. If it is cheaper, it becomes the new best solution.
Optimization is achieved by moving consignments between tours and transporters, while complying with all restrictions. Transporters can also be permanently assigned if required. The initial solution only serves as a starting point for the search for a more cost-effective alternative.
- Capacity restrictions: Optimization of shipment distribution to vans with free capacity to avoid overloading vehicles and increase efficiency.
- Time restrictions: Adjustment of the sequence of stops to meet critical time windows and prevent delays.
- General conditions: Rescheduling a shipment with cooling requirements to a vehicle with cooling equipment in order to fulfill the requirements correctly.
Route optimization takes into account driving times, driving and rest periods as well as legal requirements. As a dispatcher, breaks can be adjusted and recalculated in the event of changes so that the entire route planning complies with legal requirements. This supports the continuous optimization of processes, which is a key objective in logistics.
More efficient processes not only save time and costs, but also significantly increase customer satisfaction. Optimized route planning therefore forms the indispensable basis for successfully achieving these goals.
Authors: Lukas Klaffenböck, Java Developer Consultant; Isabella Arslan, Trainee Digital Marketing