What the study found
Allowing driver overtime in a flower retail chain’s distribution network was associated with lower routing costs. The authors report that overtime was most valuable for serving locations far from headquarters.
Why the authors say this matters
The study suggests that adding overtime to routing decisions can improve cost performance in a real delivery network. The authors also indicate that route choices and costs change when different overtime allowances are used.
What the researchers tested
The researchers studied a vehicle routing problem in a florist company in Norway with deliveries, split pickups, a heterogeneous fleet of capacitated trucks, and a heterogeneous workforce of drivers. They used a route-based mixed integer linear programming model that included ordinary driving costs, overtime costs, pickup time, and social constraints on driver workload.
What worked and what didn't
The model outperformed manually produced solutions and a commercial software package, with cost reductions of 17.4%–36.4% versus manual solutions and 9.7%–25.5% versus the commercial software. The results also showed differences in routes and costs across overtime allowances. When the objective was changed from cost minimization to distance minimization, the results could differ substantially.
What to keep in mind
The abstract does not describe limitations beyond the specific florist-company setting in Norway. The findings are based on a modeled routing problem and the results reported in the abstract do not separate effects for every individual route or site.
Key points
- The study found that driver overtime can lower routing costs in a flower retail distribution network.
- Overtime was reported as most useful for serving locations far from headquarters.
- A route-based mixed integer linear programming model was used to account for driving costs, overtime, pickup time, and driver workload constraints.
- The model beat both manual planning and commercial software, with reported cost reductions of 17.4%–36.4% and 9.7%–25.5%.
- Distance minimization could lead to results that differ substantially from cost minimization.
Disclosure
- Research title:
- Driver overtime reduced routing costs in a flower delivery network
- Authors:
- Christian Braathen, Mario Guajardo
- Institutions:
- Norwegian School of Economics
- Publication date:
- 2026-01-23
- OpenAlex record:
- View
Get the weekly research newsletter
Stay current with peer-reviewed research without reading academic papers — one filtered digest, every Friday.