Fixed or Dynamic: a short primer

Fixed route planning and dynamic route planning are two approaches used in logistics and transportation to optimize delivery routes. Here is a quick primer on these two methods

Definition:

Fixed route planning: It involves creating predefined routes that remain constant over time. Drivers follow the same routes repeatedly for their deliveries.

Dynamic route planning: It involves creating new routes each day based on known conditions at the time of planning.

Flexibility:

Fixed route planning: Provides little flexibility as routes are predetermined and remain unchanged unless explicitly modified. The lack of flexibility is actually a feature since the driver becomes very familiar with the route and their customers. It may not account for unpredictable events such as order variability or driver absences.

Dynamic route planning: Offers high flexibility as routes can be adjusted daily to optimize efficiency. It focuses on hitting time windows and minimizing cost at the expense of territory alignment and driver familiarity.

Efficiency:

Fixed route planning: Can be the most effective method when delivery patterns are consistent and predictable, and there are no significant external factors affecting the routes. It simplifies the planning process and allows for easy monitoring and compliance. Dwell time at customers is typically much lower due to familiarity between the driver and regular customers.

Dynamic route planning: Excels in scenarios with constantly changing variables, such as new delivery requests or changing order volumes. By creating new routes daily, it maximizes efficiency, reduces travel time, and optimizes resource utilization.

Optimization:

Fixed route planning: Primarily focuses on predefining routes based on historical data or predetermined rules. Typically there is separate optimization done to determine delivery days for each customer based on the frequency that they were promised. The purpose is to balance the delivery load across the work week as much as possible, making capacity planning much easier.

Dynamic route planning: Dynamic route optimization is the process of determining the most efficient and cost-effective routes for delivery drivers on a daily basis. It involves finding routes that minimize driving time and distance while considering various variables such as delivery time windows, vehicle load capacity, driver schedules, and the proximity of different stops. The algorithms are best suited to environments with high order variability and restrictive delivery time windows.

Adaptability to changes:

Fixed route planning: Requires manual intervention to accommodate changes in delivery patterns, new orders, or unforeseen disruptions. Adjusting routes may involve a time-consuming process of manual modifications.

Dynamic route planning: Responds to daily changes, automatically creating routes to ensure minimal disruptions and delays. Adjusting routes may involve even more time-consuming manual processes due to the overlapping nature of routes with time windows.

Summary: 

Both styles have their advantages and disadvantages depending on the business case. Territory based route sales will benefit the most from a fixed approach, whereas a highly variable delivery operation will need the features of the dynamic approach. In the real world most delivery operations will fall somewhere in between these two methodologies.

In future papers I will interview some high profile figures in the route optimization world to take a deeper dive into this question. Stay tuned.