Performance approximation of pick-to-belt orderpicking systems

In this paper, an approximation method is discussed for the analysis of pick-to-belt orderpicking systems. The aim of the approximation method is to provide an instrument for obtaining rapid insight in the performance of designs of pick-to-belt orderpicking systems. It can be used to evaluate the effects of changing the layout of the system, the number of picking stations, the number of pickers, the conveyor speed, the number of bins to be processed per day, the number of orderlines per bin, etc. Especially in the design phase, modeling and analysis speed is more important than accuracy. The method presented in this paper is based on Jackson network modeling and analysis. The method is fast and sufficiently accurate. The method is used by Ingenieursbureau Groenewout B.V., for early-stage evaluation of design alternatives of pick-to-belt orderpicking systems and general transportation systems

Supply-Chain Culture Clashes in Europe. Pitfalls in Japanese Service Operations

Japanese companies value service and quality highly and they put much effort in realising this. However, survey research carried out in 2001 among senior managers of Japanese logistics companies in the Netherlands, indicated that these efforts do not result in significant performance differences compared to western companies. In this exploratory paper, we report of company visits and interviews with managers of Japanese logistics companies in Western Europe. They described a clash of cultures underlying their operations, prohibiting them from achieving performance excellence. The causes focus around two key factors: the unique concept of Japanese service, based on future rewards which are absent in Western Europe; different employment circumstances in Western Europe, which make Japanese human resource management ineffective, and the Japanese career development system which makes that Japanese managers do not always have the right focus in their job abroad. We conclude that Japanese subsidiaries in Western Europe should keep on nourishing their uneq

Automated and Robotic Warehouses

The first automated, high-bay, warehouses were introduced some 50 years ago. Since then, developments have continued at a rapid pace. Initially, automation was mainly focused on pallet warehouses with bulk storage facilities. A major reason was to increase the storage density, which could be achieved by making the warehouses higher. Later, mini-load warehouses and order picking warehouses were also automated. In this paper we will discuss the different types of automated systems as well as a number of scientific results that are now known about such systems. We will first discuss storage systems for unit loads (bins and pallets). This will be followed by order picking systems from which individual packages can be picked. Finally, we will provide our future expectations of warehouse automation

Boosting revenues in the self-storage warehouse industry

__Abstract__ Self-storage is a booming industry, one that has seen remarkable growth in the United States and Europe, and across the rest of the world. While an obvious success story, new research shows that by taking a unique facility design approach, warehouse operators can do much to maximise their revenue potential

Open Location Management in Automated Warehousing Systems

A warehouse needs to have sufficient open locations to be able to store incoming shipments of various sizes. In combination with ongoing load retrievals open locations gradually spread over the storage area. Unfavorable positions of open locations negatively impact the average load retrieval times. This paper presents a new method to manage these open locations such that the average system travel time for processing a block o

The impacts of time access restrictions and vehicle weight restrictions on food retailers and the environment

Urban freight transport has many sustainable aspects. It contributes to economic vitality and the competitiveness of a region. However, the less socially and environmentally friendly effects such as noise, pollutant emissions, and nuisance, are usually the central theme in designing urban freight transport policies. Restricting policies as time access restrictions and vehicle restrictions gain popularity among Dutch local authorities. More than half of the municipalities uses time access restrictions. In spite of the popularity of these policy measures, the effects on the distribution of retailers, the environment and the transport costs are not known yet. In this paper we present three case studies of food retailers, in order to examine the effects of time access restrictions and vehicle weight restrictions. We discuss the impacts on the transport costs and the distribution processes (on the retailer’s side) and the environmental impacts. To find these effects we design five scenarios, in which we vary the length of time access restrictions, the allowed weight of the weight restriction and the number of cities in which these regulations are used. In these scenarios we adapt, based on the likely reaction of the involved food retailers, the distribution activities to fit the regulations. The results show that the vehicle weight restriction as well as the time access restrictions have a negat

Exploring retailers' sensitivity to local sustainability policies

Local governments in Western Europe increasingly use city time-access regulations to improve social sustainibility. These regulations significantly influence the distribution process of retail chain organizations. This paper studies the impact of governmental timewindow pressure on retailers’ logistical concept and consequential financial and environmental distribution performance. We determine which dimensions in the retailer’s logistical concept determine its cost and emission sensitivity to increasing time-win

On the Suboptimality of Full Turnover-Based Storage

In the past thirty years the full turnover-based storage policy as described by Hausman et al. (1976, Management Science 22(6)) has been widely claimed to outperform the commonly used ABC class-based storage policy, in terms of the resulting average storage and retrieval machine travel time. In practice however, ABC storage is the dominant policy. Hausman et al. (1976) model the turnover-based policy under the unrealistic assumption of shared storage, i.e. the stor

Optimal Storage Rack Design for a 3D Compact AS/RS with Full Turnover-Based Storage

Compact, multi-deep (3D) automated storage and retrieval systems (AS/RS) are becoming increasingly popular for storing products with relatively low turnover on a compact area. An automated storage/retrieval crane takes care of movements in the horizontal and vertical direction in the rack, and a gravity conveying mechanism takes care of the depth movement. An important question is how to layout such systems to minimize the pr

Optimal Zone Boundaries for Two-class-based Compact 3D AS/RS

Compact, multi-deep (3D), Automated Storage and Retrieval Systems (AS/RS) are becoming more common, due to new technologies, lower investment costs, time efficiency and compact size. Decision-making research on these systems is still in its infancy. We study a particular compact system with rotating conveyors for the depth movement and a Storage/Retrieval (S/R) machine for the horizontal and vertical movement of unit loads. W