Common Routing Problems—And How to Solve Them

From meandering roadways to customer requests, planning efficient routes that help your delivery business minimize expenses can prove to be virtually impossible when planning is done manually. Many of the issues you encounter while route planning is more than just common—they’re thoroughly documented logistical problems that have existed since the advent of widespread delivery. Knowing you’re not the only one encountering these issues can be helpful, but nothing compares to solving these problems and gaining the confidence that your business is operating as efficiently as possible. Mastering these problems begins with identifying them.

Vehicle Routing Problem

First named and documented in the late 1950s, the Vehicle Routing Problem (VRP) explores the logistics of routing efficiency. This problem deals with a range of variables including vehicles, drivers, depots, roads, and customers. Solving the VRP isn’t cut and dry, as there is no right or wrong solution until you determine your goals. You may want to solve it to accomplish any number of goals, such as accommodating a change in your fleet, like an unexpected breakdown; minimizing the number of delayed orders when a sudden spike in demand arises; or, most commonly, ensuring that your fleet is operating as efficiently as possible to minimize your transportation costs.

This problem is one that’s easy to identify with; it applies to virtually any scenario in which a delivery needs to be made. You have a fleet of vehicles, a team of drivers, and a number of parcels to be delivered from one or more depots. The more components you add in, the more complicated the problem becomes.

Vehicle Routing Problem With Time Windows

As the name suggests, the Vehicle Routing Problem with Time Windows (VRPTW) expands on the VRP by introducing specific time windows in which deliveries must be made. These designated time windows add a layer of complexity that requires additional attention when optimizing a route to be as efficient as possible.

Adding time windows has a drastic impact on how deliveries can be routed. Conflicting time windows can dictate not only which route is potentially the most efficient, but also which parcels can be loaded onto the same vehicles. When routing manually, this doubles the work involved in the route planning process; you must first assign time-sensitive parcels to the correct vehicles, then add in the rest of your parcels and plan routes that accommodate each necessary time window. If you then discover that parcels on the same vehicle conflict somehow, you’re back to square one.

In a real-world setting, dealing with customer restraints like time windows is one of the most common hurdles that route planners need to overcome. If time windows aren’t being met, problems like refused deliveries, unsatisfied customers, poor reviews, and canceled contracts are sure to follow.

Vehicle Routing Problem With Pickup and Delivery

While many models focus on delivering parcels that originate from one or more central depots, the Vehicle Routing Problem with Pickup and Delivery (VRPPD) considers how to operate most efficiently when drivers are required to interact with a number of pickups and deliveries—and their corresponding locations—throughout the course of their route.

A rapidly growing example of the VRPPD is meal pickup and delivery. For instance, consider a driver who is tasked with delivering meals from several different restaurants to a number of customers. Solving the VRPPD can provide an optimal route for ensuring both pickups and deliveries are carried out efficiently.

The need for pickups to precede their corresponding deliveries, of course, means that the order of stops can be very different than if the same locations are input and viewed from the perspective of the standard VRP. In many cases, including the food delivery route we mentioned, outside factors like maximum travel time between pickup and delivery may come into play to ensure freshness and customer satisfaction, further complicating the process of finding the optimal route.

Capacitated Vehicle Routing Problem

Vehicle cargo capacity is crucial when planning your routes. The Capacitated Vehicle Routing Problem (CVRP) aims to solve this, taking vehicle restrictions into account while still solving for overall efficiency within these established parameters.

Every vehicle in your fleet has maximum capacities in terms of cargo weight and volume. Failing to plan for both can have significant repercussions. Volumetric capacity problems are immediately noticeable, requiring you to revisit your plans when a planned parcel is unable to fit onto the designated vehicle. Weight problems can cause significant delays, as well, whether the problem manifests as exceeding the weight limits along a given route or avoidable vehicle maintenance issues due to exceeding the vehicle’s recommended weight capacities.

Finding Solutions for Common Routing Problems

To solve any of these routing problems manually draw on your resources in the form of manpower and hours of labor. Manual route planning for even a relatively small delivery business tends to rely on a vast array of spreadsheets, maps, and notes, and ultimately fails to provide any genuine degree of confidence that the route you settle on is the most efficient option. The time saved with a relatively efficient route may be negated by the time spent planning it if the planning process is done manually. Manual route planning also fails when last-minute changes need to be accommodated, often requiring that the process be restarted from scratch.

As you add more variables, such as those considered by the VRPTW, VRPPD, and CVRP, the complexity compounds to make finding the most efficient route within those parameters even more challenging. These variables are easy to factor into the equation of your business’s vehicle routing problems, though, when you optimize your routes using a sophisticated algorithm. By saving you time during the process of route planning, as well as while your routes are being completed, a route optimization tool is the key to ensuring your delivery business is operating as efficiently as it can be. To learn more about the benefits of true route optimization and how technology can solve common routing problems, explore WorkWave Routing Engine today.