Stefan Schwerdfeger

Friedrich Schiller University Jena | FSU · Chair for Management Science/Operations Management

In view of success stories of unicorn startups from the sharing and gig economy such as Airbnb, DiDi, or Uber, it is not surprising that postal service providers try to transfer the sharing idea toward their last-mile delivery services: owners of under-used assets (here private crowdshippers traveling anyway) are connected with users willing to pay...

Underground passageways for the transport of goods and people have fascinated mankind throughout the centuries. Recent initiatives in different parts of the world aim at rekindling the freight tunnel concept for urban logistics. According to this concept, freight is lifted into a tunnel, moved via electrically powered vehicles, rail cars, or maglev...

Electrifying road-based long-haul transportation is an intricate task. Given the current state of battery technology, either the driving ranges of electric commercial vehicles (ECVs) are too short or high-capacity batteries are costly and so heavy that payloads are limited. An old, yet recently revitalized, charging infrastructure currently evaluat...

To avoid traffic accidents due to driver fatigue in long-haul trucking, there are laws and provisions all over the world that regulate breaks and rest periods of truck drivers. When aiming to follow the existing hours of service regulations, however, parking space for trucks in service areas is often scarce, especially along crowded mainlines. In t...

Stationary parcel lockers have established as useful delivery options, especially for those households where nobody is at home during typical parcel delivery times. However, having to move toward a locker, maybe after a tiring workday, can be inconvenient for customers. Mobile parcel lockers, especially when driving autonomously, can be positioned...

Triggered by the great success of e-commerce, today’s warehouses more and more evolve to fully-automated fulfillment factories. Many of them follow the parts-to-picker paradigm and employ shelf-lifting mobile robots or conveyors to deliver stock keeping units (SKUs) to stationary pickers operating in picking workstations. This paper aims to structu...

High-occupancy vehicle (HOV) lanes are restricted traffic lanes that are reserved for vehicles with multiple car occupants. Depending on the current number of passengers, a driver must either travel slower on the often-congested general-purpose lane or can access the faster HOV lane. In this paper, we provide optimization approaches for matching su...

Given the current state of battery technology, applying electric trucks for long-haul transportation is a cumbersome task. Either the driving ranges are too short or high-capacity batteries are so heavy that payloads are limited. An old, yet recently revitalized charging infrastructure, currently evaluated on multiple test tracks all around the glo...

A moving walkway (also denoted as moving sidewalk, travelator, autowalk, pedestrian conveyor, or skywalk) is a slow moving conveyor that transports standing or walking people horizontally over a short to medium distance. Constantly moving walkways have a long-lasting tradition especially inside large buildings, such as airport terminals and railway...

Seeing the huge success of sharing platforms such as Uber, Lyft, and Airbnb, where owners of under-used assets are connected with users willing to pay for the use of these assets, it is not surprising that retailers aim to transfer the basic idea of the sharing economy to their last-mile deliveries. In crowdshipping, the under-used assets are trans...

In the wake of e-commerce and its successful diffusion in most commercial activities, last-mile distribution causes more and more trouble in urban areas all around the globe. Growing parcel volumes to be delivered toward customer homes increase the number of delivery vans entering the city centers and thus add to congestion, pollution, and negative...

Several technological developments are on the way to substantially impact future railway operations. Distributed traction power enables operating longer and heavier trains. The use of automatic couplings allows to quickly join formerly separately operated trains to longer units. Such a platooning on rails promises a much better utilization of conge...

To transfer export cars on board of car carrier vessels in vehicle transshipment terminals or to rebalance the vehicles of car sharing providers in urban areas, plenty of car relocation moves need to be processed. Often in these settings, a team of drivers cooperates to execute a given set of car movements. They are chauffeured by a taxi towards th...

In the era of e-commerce and just-in-time production, an efficient supply of goods is more than ever a fundamental requirement for any supply chain. In this context, this paper summarizes the author’s dissertation about optimization in outbound logistics, which received the dissertation award of the German Operations Research Society (GOR) in the c...

To reduce congestion, environmental damage, and negative health impact in large urban areas plenty novel concepts for last-mile distribution have been innovated in the recent years. The concept treated in this paper are mobile parcel lockers that are able to change their locations during the day, either autonomously or moved by a human driver. By r...

The sharing economy, i.e., the cooperative consumption of goods and services offered by private households or companies via online market places, gains more and more attention. Most sharing platforms coordinate transactions by generating each consumer an individual list of suited and available resources to choose from. If plenty online requests arr...

Last mile deliveries with unmanned aerial vehicles (also denoted as drones) are seen as one promising idea to reduce excessive road traffic. To overcome the difficulties caused by the comparatively short operating ranges of drones, an innovative concept suggests to apply trucks as mobile landing and take‐off platforms. In this context, the paper on...

A-Frame systems are among the most efficient order picking devices. Stock keeping units are stockpiled in vertical channels successively arranged along an A-shaped frame and a dispenser automatically fiips the bottom most item(s) of each channel into totes or shipping cartons that pass by under the frame on a conveyor belt. While order picking itse...

To reduce the negative impact of excessive traffic in large urban areas, many innovative concepts for intelligent transportation of people and freight have recently been developed. One of these concepts relies on autonomous delivery robots launched from trucks. A truck loads the freight dedicated to a set of customers in a central depot and moves i...

In Schwerdfeger and Walter (2016), we proposed a subset sum based improvement procedure (denoted by LS) for solving the problem of minimizing the normalized sum of squared workload deviations on m identical machines. In its core, the algorithm builds on an exact procedure (denoted by WB3) for the case of m=3 machines. Although this approach proved...

Platooning has been identified as a promising way to reduce the carbon footprint and fuel consumption of freight transportation. Recent technological developments connecting a platoon via digital data transmission even allow that the driver of the front truck controls all (unmanned) follower vehicles. Existing research mainly focuses on the technol...

Integrating far-distant suppliers, e.g., from low-wage countries and other currency areas, into concerted just-in-time (JIT) supply concepts is a delicate planning task. One enabler, e.g., often applied in the automotive industry, is an intermediate cross-docking terminal. Such a cross-dock located in close vicinity to the targeted plant is supplie...

This paper addresses the max–min (Formula presented.)-partitioning problem that asks for an assignment of n jobs to m parallel machines so that the minimum machine completion time is maximized and the number of jobs on each machine does not exceed a machine-dependent cardinality limit (Formula presented.)(Formula presented.). We propose different p...

This paper treats an order picking system where a crane continuously relocates stock keeping units (SKUs) in a high-bay rack subdivided into the bottommost picking level and the upper reserve area. The capacity of the pick face is not large enough to store all SKUs, so that the crane has to ensure that all SKUs demanded by a current picking order a...

The paper on hand addresses the workload balancing problem that asks for an assignment of n independent jobs to m identical parallel machines so that the normalized sum of squared workload deviations (NSSWD-criterion) is minimized. For the special case of m=3 machines we propose an exact algorithm that requires solving a sequence of subset sum prob...