Large Neighborhood Search for rich VRP with multiple pickup and delivery locations

In this paper we consider a rich vehicle routing problem where transportation requests are characterised by multiple pickup and delivery locations. The problem is a combined load acceptance and generalised vehicle routing problem incorporating a diversity of practical complexities. Among those are time window restrictions, a heterogeneous vehicle fleet with different travel times, travel costs and capacity, multi-dimensional capacity constraints, order/vehicle compatibility constraints, and different start and end locations for vehicles. We propose iterative improvement approaches based on Large Neighborhood Search and a relatedness measure for transportation requests with multiple pickup and delivery locations. Our algorithms are characterised by very fast response times and thus, can be used within dynamic routing systems where input data can change at any time

Drivers’ working hours in vehicle routing and scheduling

Although of particular importance for many reallife applications, restrictions to drivers’ working hours have only received very little attention in the vehicle routing literature. Regulations regarding drivers’ working hours often have a big impact on total travel times, i.e. the time required for driving, breaks, and rest periods. In this paper we describe the regulations for drivers’ working hours in the European Union. We present the Vehicle Routing Problem with Drivers’ Working Hours (VRPDWH) which generalises the well-known Vehicle Routing Problem with Time Windows. We present a Large Neighbourhood Search algorithm and test cases for the VRPDWH and conclude this paper with computational experiments

A General Vehicle Routing Problem

In this paper, we study a rich vehicle routing problem incorporating various complexities found in real-life applications. The General Vehicle Routing Problem (GVRP) is a combined load acceptance and generalised vehicle routing problem. Among the real-life requirements are time window restrictions, a heterogeneous vehicle fleet with different travel times, travel costs and capacity, multi-dimensional capacity constraints, order/vehicle compatibility constraints, orders with multiple pickup, delivery and service locations, different start and end locations for vehicles, and route restrictions for vehicles. The GVRP is highly constrained and the search space is likely to contain many solutions such that it is impossible to go from one solution to another using a single neighbourhood structure. Therefore, we propose iterative improvement approaches based on the idea of changing the neighbourhood structure during the search

A Roadmap for Sustainable Freight Transport

It is expected that freight transport in the European Union will grow significantly and road transport will account for a major part of this growth. By 2020 almost 30% of CO2 emissions in the European Union will be caused by transportation. It is obvious that our present patterns of transport growth are unsustainable. One way toward more sustainable transport is to explicitly take greenhouse gas emissions into account in logistics decisions and to get freight traffic to switch from roads to alternative transport modes. This contribution discusses drivers and opportunities for intermodal transport planning. Related literature is surveyed and fields for future research are identified

Lenk- und Ruhezeiten in der Tourenplanung

Am 11. April 2007 werden in der Europäischen Union neue Vorschriften bezüglich der Lenk- und Ruhezeiten im Straßengütertransport in Kraft treten. Den neuen Vorschriften zufolge können Spediteure und Verlader für Verstöße der Fahrer haftbar gemacht werden. Da zudem Lenk- und Ruhezeiten einen signifikanten Einfluss auf Reisezeiten haben, ist eine Berücksichtigung der entsprechenden Regelungen bei der Tourenplanung unumgänglich. In diesem Beitrag wird gezeigt wie die neuen EU-Vorschriften in die Tourenplanung eingebracht werden können und das Vehicle Routing Problem mit Lenk- und Ruhezeiten (VRPLR) vorgestellt

Collaborative Dispatching of Commercial Vehicles

Collaborative dispatching allows several dispatchers to view the routing solution as a dynamic model where changes to the vehicle routes can be made in real-time. In this paper we discuss implications of collaborative dispatching on real-time decision support tools for motor carriers. We present a collaborative dispatching system which uses real-time information obtained from a telematics system. Messages sent from the vehicles are automatically analysed and actual data, such as exact arrival and departure times, as well as discrepancies between actual and planned data are identified. The collaborative dispatching system not only allows several dispatchers to concurrently modify the schedule, but also a dynamic optimisation method. The optimisation method is capable of taking into account that input data may change at any time and that dispatchers can concurrently modify the schedule and may add or relax certain constraints relevant to the optimisation model

Workforce Scheduling with Order-Picking Assignments in Distribution Facilities

Scheduling the availability of order pickers is crucial for effective operations in a distribution facility with manual order pickers. When order-picking activities can only be performed in specific time windows, it is essential to jointly solve the order picker shift scheduling problem and the order picker planning problem of assigning and sequencing individual orders to order pickers. This requires decisions regarding the number of order pickers to schedule, shift start and end times, break times, as well as the assignment and timing of order-picking activities. We call this the order picker scheduling problem and present two formulations. A branch-and-price algorithm and a metaheuristic are developed to solve the problem. Numerical experiments illustrate that the metaheuristic finds near-optimal solutions at 80% shorter computation times. A case study at the largest supermarket chain in The Netherlands shows the applicability of the solution approach in a real-life business application. In particular, different shift structures are analyzed, and it is concluded that the retailer can increase the minimum compensated duration for employed workers from six hours to seven or eight hours while reducing the average labor cost with up to 5% savings when a 15-minute flexibility is implemented in the scheduling of break times

A Roadmap for Sustainable Freight Transport

It is expected that freight transport in the European Union will grow significantly and road transport will account for a major part of this growth. By 2020 almost 30% of CO2 emissions in the European Union will be caused by transportation. It is obvious that our present patterns of transport growth are unsustainable. One way toward more sustainable transport is to explicitly take greenhouse gas emissions into account in logistics decisions and to get freight traffic to switch from roads to alternative transport modes. This contribution discusses drivers and opportunities for intermodal transport planning. Related literature is surveyed and fields for future research are identified