Operations Research, Systems Engineering and Industrial Engineering Commons^™

Spiral Facility Layout Generation And Improvement Algorithm, Hatice E. Sanli, Fahrettin Eldemir

11th IMHRC Proceedings (Milwaukee, Wisconsin. USA – 2010)

This study is concerned with construction and improvement of a facility layout heuristic called Spiral Facility Layout Generation and Improvement Algorithm (SFLA). The algorithm starts with positioning departments from center point and continues like a hologram from center to outside. The aim of any facility layout algorithm is to better allocate the departments within facility. SFLA is compared with the existing space filling curve methods, MCRAFT and MULTIPLE, that are available in the literature. To form an initial spiral curve, a block system is used, like the bands for MCRAFT. The width and length of the blocks are given by …

Empirically-Based Warehouse Design: Can Academics Accept Such An Approach?, James M. Apple Jr., Russell D. Meller, John A. White Jr.

11th IMHRC Proceedings (Milwaukee, Wisconsin. USA – 2010)

It is our opinion that existing research is not sufficient to support the design of a warehouse. As a result, facility designers that work in practice are left to face the design process with their own methods. These methods are in stark contrast to the analytical models developed in academia in that they are highly based on empirical observations. Supported by a collection of empirical observations, facility designers who work in practice employ an ad hoc design process. We present a design process based on empirical observations and then formalize it so that it can be taught and used. We …

Dispatching Vehicles Considering Uncertain Handling Times At Port Container Terminals, Vu Duc Nguyen, Kap Hwan Kim

11th IMHRC Proceedings (Milwaukee, Wisconsin. USA – 2010)

This paper considers the problem of vehicle dispatching at port container terminals in a dynamic environment. The problem deals with the assignment of delivery orders of containers to vehicles while taking into consideration the uncertainty in the travel times of the vehicles. Thus, a real-time vehicle dispatching algorithm is proposed for adaptation to the dynamic changes in the states of the container terminals. To evaluate the performance of the proposed algorithm, a simulation study was conducted by considering various values of decision parameters under the uncertainty in travel times. Further, the performance of the proposed algorithm was compared with those …

Blocking Effects On Performance Of Warehouse Systems With Automonous Vehicles, Ananth Krishnamurthy, Sunderesh Heragu, Charles Malmborg

11th IMHRC Proceedings (Milwaukee, Wisconsin. USA – 2010)

Distribution centers are under increasing pressure to adopt material handling systems that offer greater flexibility to improve cycle time and throughput capacity in the transfer of unit loads in their high density storage areas. Autonomous Vehicles-based Storage and Retrieval Systems (AVS/RS), have been shown to hold significant promise in this context. In these systems, loads are transferred by autonomous vehicles. Vehicles support horizontal load movement along aisles and cross-aisles within a tier, and lifts support vertical movement between tiers. Existing research in AVS/RS, do not explicitly account for the potential blocking of vehicles and lifts while they are processing transactions. …

Merge Problems With High Speed Sorters, Dirk Jodin, Andreas Wolfschluckner

11th IMHRC Proceedings (Milwaukee, Wisconsin. USA – 2010)

To meet customer demands on distribution the necessity of sorting systems for unit loads in regard to quantity and capacity is growing up constantly.

Due to that, manufactures offer powerful sorting machines with a capacity up to 15.000 pieces per hour. Those machines are for instance Crossbelt or Tilt-Tray sorters. The output of these sorters is calculated by the equation of throughput.

The point of interest is the merge, referring to the overall efficiency of the single sorter. The motion sequence during merging has to be absolutely quick and precise to achieve exact positioning using minimized distances of the single …

The Future Of Modeling In Material Handling Systems, Leon F. Mcginnis

11th IMHRC Proceedings (Milwaukee, Wisconsin. USA – 2010)

Today, when we talk about “modeling” in the context of material handling systems, invariably we are referring to a mathematical or computational model for analyzing some aspect of the system, such as its throughput rate, response time, cost of ownership, required storage capacity, etc. Creating these kinds of models requires considerable knowledge in at least two domains the material handling system domain, and the analysis methodology domain—and considerable skill in the “art of modeling” in order to express the former in the terms of the latter. The results can be somewhat ad hoc—e.g., two different modelers are likely to create …

Optimizing Distribution Center Configuration: A Practical View Of A Multi-Objective Problem, Russell D. Meller, Lisa M. Thomas

11th IMHRC Proceedings (Milwaukee, Wisconsin. USA – 2010)

The shape of a distribution center, as well as whether dock locations are on one side or two sides of the facility, impacts measures like travel distances and the number of dock locations that may be utilized. Thus, for a required number of pallet locations, there are multiple combinations of distribution center shape and dock configurations that should be evaluated against multiple measures. We have developed a practical model for making such evaluations and illustrate the model with data reflective of a partner in the Center for Engineering Logistics and Distribution.

The Effect Of Interaction Between The Production System (Ps) And A Looped Conveyor-Based Material Handling System (Lcmhs) In A Manufacturing Facility, Vernet Lasrado, Dima Nazzal

11th IMHRC Proceedings (Milwaukee, Wisconsin. USA – 2010)

In this paper, we provide empirical evidence that shows the effect of the interaction between the production system (PS) and a looped conveyor-based material handling system (LCMHS) in a manufacturing facility. A rudimentary simulation model captures the interaction between the two systems. Varying several key factors, we test for a statistically significant difference in the work in process (WIP) of the production system with and without the LCMHS to find if the squared coefficient of variation (SCV) of the interarrival time distribution to the PS is affected. The results suggest the need to model the interaction between the two systems …

Design Of Warehouse For Material, Which Is Non-Uniform And Difficult To Handle, Andrea Seidlova, David Sourek

11th IMHRC Proceedings (Milwaukee, Wisconsin. USA – 2010)

Main goal of this paper is warehouse layout optimization with emphasis on maximum space utilization. It is about rack system design, which leads to capacity maximization of warehouse for non-uniform material with heavy weight. The warehouse system has to enable at least partial automation (the possibility to use AS/RS system), minimization of service time and minimization of man effort. Initial constraining conditions for warehouse design in our case are warehouse area, maximum load of racks or shelves, maximum allowed floor load and existing location of arrival road for material loading and unloading.

Webasrs – A Web-Based Tool For Modeling And Design Of Abstract Unit-Load Picking Systems, Jeffrey S. Smith, Sabahattin Gokhan Ozden

11th IMHRC Proceedings (Milwaukee, Wisconsin. USA – 2010)

This paper describes a web-based tool that supports the modeling and design of abstract unit-load picking systems. The term “abstract” implies that the model is not specific to any equipment or vendors’ products, but, instead, focuses on the generic system components such as pallets, racks, slots, forklifts, cranes, etc. that comprise typical unitload picking systems. The objectives of the tool are to support the design of an AS/RSbased or a manual forklift-based picking system based on a set of design parameters and to be able to convert from an AS/RS design to a flat warehouse design and vice versa. The …

A Flowshop Scheduling Problem With Transportation Times And Capacity Constraints, Abraham Mendoza, Jose A. Ventura, Kwei Long Huang

11th IMHRC Proceedings (Milwaukee, Wisconsin. USA – 2010)

Although there are numerous methodologies and research studies on machine scheduling, most of the literature assumes that there is an unlimited number of transporters to deliver jobs from one machine to another for further processing and that transportation times can be neglected. These two assumptions are not applicable if one intends to generate an accurate schedule for the shop floor. In this research, a flowshop scheduling problem with two machines, denoted as M1 and M2, and a single transporter with capacity c is considered. The main focus is on the development of a dynamic programming algorithm to generate a schedule …

Optimization Of Costs And Service Level By Choosing The Best Customer Order Decoupling Point, Michael Schmidt, Detlef Spee

11th IMHRC Proceedings (Milwaukee, Wisconsin. USA – 2010)

The customer order decoupling point (CODP) as the link in the supply chain between processes based on uncertain information, such as sales forecasts, and certain information in the form of customer orders is crucial for production efficiency, storage costs, and the quality of logistics. This paper focuses on developing an approach for identifying a CODP that provides the highest potential for achieving business objectives. Within the context of the above-mentioned topics, this paper focuses on the interrelations and the tradeoffs that have to be made when positioning the COPD. The goal of the paper is to present an effective and …

Distribution Planning Considering Warehousing Decisions, Pratik J. Parikh, Xinhui Zhang, Bhanuteja Sainathuni

11th IMHRC Proceedings (Milwaukee, Wisconsin. USA – 2010)

Modern supply chains heavily depend on warehouses for rapidly fulfilling customer demands through retail, web-based, and catalogue channels. The traditional approach that considers warehouses as cost-centers has affected the profitability of numerous supply chains. A lack of synchronization between procurement and allocation decisions causes warehouses to scramble for resources during peak times and be faced with under-utilized resources during drought times. Warehouses, however, have emerged as service-centers and it is imperative that warehousing decisions be an integral part of supply chain decisions. In this paper we propose a mixed-integer programming model to integrate warehousing decisions with those of inventory and …

Gains In The Life-Cycle Of Adaptable, Self-Organizing Material Handling Systems, Jan R. Nopper, Guido Follert, Michael Ten Hompel

11th IMHRC Proceedings (Milwaukee, Wisconsin. USA – 2010)

Compared to conventional material flow controls, self-organized material handling systems and the Internet of Things in facility logistics promise several advantages during the life-cycle. Most important is the increased adaptability in case of expansions or modifications due to a consistent modular design; this also promotes an increased robustness due to clearly defined interfaces and a decreased complexity of each module. The use of RFID technology increases the availability of real-time data about the system and the transported units. However, the introduction of self-organized material handling systems also causes costs, e.g. for necessary RFID tags and readers. Against this background, it …

Determining Warehouse Storage Location Assignments Using Clustering Analysis, Carl Egas, Dale Masel

11th IMHRC Proceedings (Milwaukee, Wisconsin. USA – 2010)

The methodology used to assign products to a storage location in a warehouse can have a significant impact on the amount of time required to retrieve all of the items needed to fill an order. This paper describes a methodology that uses a clustering approach to determine storage assignments, where the metric of the strength of the relationship between two stock-keeping units (SKUs) is the number of times that the SKUs appear in the same order. Clustering is performed to maximize the frequency with which SKUs in the same cluster are ordered together. In testing, the clustering assignments were compared …

Using Data Envelopment Analysis To Evaluate The Performance Of Third Party Distribution Centers, Ching-Jung Ting, Hsueh-Lin Fang

11th IMHRC Proceedings (Milwaukee, Wisconsin. USA – 2010)

There has been considerable interest worldwide in last few years in the growth of third party logistics (3PL) providers. 3PL distribution center (DC) enables firms to achieve reduced operating costs, increased revenues, and to focus on their core competence. This research aims to find the key performance indicators through a survey of a set of DCs and then evaluate their efficiency over the period 2005-2007 using data envelopment analysis (DEA) models based on selected performance indicators as inputs and outputs. Three inputs and two outputs for all DCs from the surveyed performance indicators were selected in this study. DEA is …

Freight Sequencing To Improve Hub Operations In The Less-Than-Truckload Freight Transportation Industry, Xiangshang Tong, Kimberly Ellis, Amy Brown Greer

11th IMHRC Proceedings (Milwaukee, Wisconsin. USA – 2010)

In less-than-truckload freight transportation, hub operations affect the service levels that carriers are able to provide their customers. This paper focuses on improving the efficiency of hub operations by reducing freight handling time and cost. Specifically, the freight sequencing problem (FSP) is investigated to determine the freight unloading and loading sequence that minimizes the time for dock workers to transfer shipments from origin trailers to destination trailers. The FSP is modeled as a Rural Postman Problem (RPP) and three algorithms are compared: trailer-at-atime, nearest neighbor, and balance-and-connect. Using five industrial data sets, the results demonstrate the effectiveness, advantages, and disadvantages …

Analysis Of Picker Blocking In Narrow-Aisle Batch Picking, Soondo Hong, Andrew L. Johnson, Brett A. Peters

11th IMHRC Proceedings (Milwaukee, Wisconsin. USA – 2010)

This study analyzes impacts by batch picking on picker blocking in narrow-aisle order picking, and determines appropriate batch formations for a better order picking throughput. We present multiple-pick analytical models to offer insights about picker blocking in batch picking. Several simulation studies over a variety of batching situations scrutinize order batching situations which give throughput benefits in narrow-aisle configurations by satisfying the analytical results. Our results highlight three findings for narrow-aisle batch picking processes: 1) variation of pick probability in batch picking is inevitable and is a primary driver of picker blocking; 2) a near-optimal distance-based batching algorithm can experience …

Towards A Physical Internet: The Impact On Logistics Facilities And Material Handling Systems Design And Innovation, Benoit Montreuil, Russell D. Meller, Eric Ballot

11th IMHRC Proceedings (Milwaukee, Wisconsin. USA – 2010)

Aiming for a radical sustainability improvement, the Physical Internet has the potential of revolutionizing the fields of material handling, logistics, transportation and facilities design. It exploits the enabling concept of standardized, modular and smart containers as well as the universal interconnectivity of logistics networks and services. Its underlying paradigm shift creates a tremendous breakthrough innovation opportunity for the material handling and facility logistics community in terms of equipment, systems and facility design and operation. This paper provides a primer overview of a key subset of the physical elements serving as the foundation of the Physical Internet infrastructure, classified in three …

Multiple-Grooved Magnetic Traction Sheaves, Thorsten Schmidt, Thomas Leonhardt, Martin Anders

11th IMHRC Proceedings (Milwaukee, Wisconsin. USA – 2010)

This paper discusses a new and innovative form of traction sheaves, which can be used in many hoisting applications that are driven with wire ropes in material handling systems. By use of high performance permanent magnets, integrated in the periphery of traction sheaves, a significant increase of driving capacity is achieved. In this special case it concerns high energy magnets consisting of rare earth materials known as NdFeB magnets. These magnets provide a 20 times higher force than conventional magnets. The results of the research show that the driving capacity of traction sheaves with a round groove design can be …