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Full-Text Articles in Industrial Engineering

Simulation And Optimization Of Ant Colony Optimization Algorithm For The Stochiastic Uncapacitated Location-Allocation Problem, Jean-Paul Arnaout, Georges Arnaout, John El Khoury Oct 2016

Simulation And Optimization Of Ant Colony Optimization Algorithm For The Stochiastic Uncapacitated Location-Allocation Problem, Jean-Paul Arnaout, Georges Arnaout, John El Khoury

Engineering Management & Systems Engineering Faculty Publications

This study proposes a novel methodology towards using ant colony optimization (ACO) with stochastic demand. In particular, an optimizationsimulation-optimization approach is used to solve the Stochastic uncapacitated location-allocation problem with an unknown number of facilities, and an objective of minimizing the fixed and transportation costs. ACO is modeled using discrete event simulation to capture the randomness of customers’ demand, and its objective is to optimize the costs. On the other hand, the simulated ACO’s parameters are also optimized to guarantee superior solutions. This approach’s performance is evaluated by comparing its solutions to the ones obtained using deterministic data. The results …


Improvement Of Work Process Performance With Task Assignments And Mental Workload Balancing, Cansu Kandemir Oct 2016

Improvement Of Work Process Performance With Task Assignments And Mental Workload Balancing, Cansu Kandemir

Engineering Management & Systems Engineering Theses & Dissertations

The outcome of a work process depends heavily on which tasks assigned to which employees. However, sometimes-optimized assignments based on employees’ qualifications may result in an uneven and ineffective workload distribution among them. Likewise, an even workload distribution without considering the employee's qualifications may cause unproductive employee-task matching that results in low performance of employees. This trade-off is even more noticeable for work processes during critical time junctions, such as in military command centers and emergency rooms that require being fast and effective without making errors.

This study proposes that optimizing task-employee assignments according to their capabilities while also keeping …


An Engineering Approach To Industrial Research And Development Of Pillows, Wesley Patterson Aug 2016

An Engineering Approach To Industrial Research And Development Of Pillows, Wesley Patterson

Mahurin Honors College Capstone Experience/Thesis Projects

Comfort during sleep, though taken for granted, involves a great amount of research and engineering. Few give it a second thought, but nearly one-third of a person’s life is spent with their head on a pillow, thus making them a point for increased quality. Having been approached by a tier-1 bedding manufacturer, a team of both mechanical and electrical engineers was been tasked with the goal of creating a valid research tool that the customer, Tempur-Sealy, will utilize in the company’s research and development of high-end pillows. The team sought to tackle this project utilizing tools and knowledge gained throughout …


Best Matching Processes In Distributed Systems, Mohsen Moghaddam Aug 2016

Best Matching Processes In Distributed Systems, Mohsen Moghaddam

Open Access Dissertations

The growing complexity and dynamic behavior of modern manufacturing and service industries along with competitive and globalized markets have gradually transformed traditional centralized systems into distributed networks of e- (electronic) Systems. Emerging examples include e-Factories, virtual enterprises, smart farms, automated warehouses, and intelligent transportation systems. These (and similar) distributed systems, regardless of context and application, have a property in common: They all involve certain types of interactions (collaborative, competitive, or both) among their distributed individuals—from clusters of passive sensors and machines to complex networks of computers, intelligent robots, humans, and enterprises. Having this common property, such systems may encounter common …


Solar Turbines Compressor Blade Installation Tools, Ryan Bruce, Carolyn Honeycutt, Stephen Oltrogge, Emmett Ross Jun 2016

Solar Turbines Compressor Blade Installation Tools, Ryan Bruce, Carolyn Honeycutt, Stephen Oltrogge, Emmett Ross

Mechanical Engineering

The following report documents a California Polytechnic State University, Mechanical Engineering Senior Project sponsored by the gas turbine manufacturer, Solar Turbines. The senior project team consisted of four senior mechanical engineering students at Cal Poly, all with general concentrations; Ryan Bruce, Carolyn Honeycutt, Steve Oltrogge, and Emmett Ross. Kenneth Thomas sponsored the group and serves as the point of contact between the senior project team and Solar Turbines. He is a member of the Solar Turbines Mechanical Design Engineering Team and a Cal Poly graduate. Christoph Maurer served as the project team’s on-campus advisor.

A gas turbine uses internal combustion …


Using Value-Focused Thinking For Engineered Resilient Systems, Colin A. Small May 2016

Using Value-Focused Thinking For Engineered Resilient Systems, Colin A. Small

Industrial Engineering Undergraduate Honors Theses

The DoD needs their systems to be resilient in the face of an ever changing world. To increase resilience in future systems the DoD has created a program called Engineered Resilient Systems. Resilience can be broken down into two parts, mission and platform resilience. Mission resilience is the ability of a system to repel, resist, absorb, and recover from environments and threats that occur on planned missions. Platform resilience is the ability of a system platform to adapt to new missions and new threats.

The University of Arkansas department of Industrial Engineering is working for the ERS program researching resilience. …


Modeling Supply Chain Resiliency, Jeff A. Hazel May 2016

Modeling Supply Chain Resiliency, Jeff A. Hazel

Industrial Engineering Undergraduate Honors Theses

Engineered Resilient Systems (ERS) is a Department of Defense (DoD) program focusing on the effective and efficient design and development of complex engineered systems throughout their life cycle. There is a growing literature with qualitative definitions of resilience and quantitative models for systems with one performance measure. This paper uses a quantitative resilience framework (the Framework for ERS) that includes system design options, reliability, threats, vulnerabilities, responses, and consequences assessed in multiple system performance measures. The framework assists in establishing a model for any system to evaluate resiliency. This paper applies this framework using Multiple Objective Decision Analysis (MODA) to …


Production And Inventory Control In Complex Production Systems Using Approximate Dynamic Programming., Han Wu May 2016

Production And Inventory Control In Complex Production Systems Using Approximate Dynamic Programming., Han Wu

Electronic Theses and Dissertations

Production systems focus not only on providing enough product to supply the market, but also on delivering the right product at the right price, while lowering the cost during the production process. The dynamics and uncertainties of modern production systems and the requirements of fast response often make its design and operation very complex. Thus, analytical models, such as those involving the use of dynamic programming, may fail to generate an optimal control policy for modern production systems. Modern production systems are often in possession of the features that allow them to produce various types of product through multiple working …


Engineered Resilient Systems Model Applied To Network Design, Zephan W. Wade May 2016

Engineered Resilient Systems Model Applied To Network Design, Zephan W. Wade

Industrial Engineering Undergraduate Honors Theses

Engineered Resilient Systems (ERS) is a Department of Defense (DoD) program focusing on the effective and efficient design and development of resilient complex engineered systems throughout their lifecycle. There is growing literature with qualitative definitions of resilience and quantitative models for systems, but these focus typically on systems with one performance measure. In application, many systems have multiple functions and multiple performance measures. This research uses a quantitative resilience framework for ERS that includes system design options, reliability, external threats, vulnerabilities, responses, and consequences assessed on multiple system performance measures. This paper applies the ERS framework to designing resilient networks.


Use Of Response Surfaces In The Design Of A Simple Step Stress Accelerated Test Plan, Alexander H. Wong May 2016

Use Of Response Surfaces In The Design Of A Simple Step Stress Accelerated Test Plan, Alexander H. Wong

Graduate Theses and Dissertations

In designing accelerated testing plans, cost is a factor that is missing in much of the literature. This paper explicits considers cost by developing an optimization model with the objective to minimize costs for a simple step stress accelerated test plan. Two methodologies are employed. One is an optimization approach in which an attempt is made to quantify the behavior of a series-parallel hardware system over all stages of testing using a response surface, and then an optimization model is used to determine the settings for stresses and failure mode modifications for all stages of testing prior to the start …


A Tabu Search, Augment-Merge Heuristic To Solve The Stochastic Location Arc Routing Problem, Tiffany L. Yang May 2016

A Tabu Search, Augment-Merge Heuristic To Solve The Stochastic Location Arc Routing Problem, Tiffany L. Yang

Graduate Theses and Dissertations

The location arc routing problem (LARP) is a network optimization problem combining strategic facility location decisions and tactical or operational vehicle routing decisions for customer demand located on arcs of a network. The LARP seeks to locate facilities, or depots, and create vehicle delivery routes to minimize costs. The total cost is comprised of three components: fixed facility locations costs, fixed route creation (or vehicle acquisition) costs, and variable arc traversal costs. The applications of the LARP are varied and often include public services such as mail delivery, garbage collection, and street sweeping. In all of these applications, the magnitude …


Application Of Smart Factory Design In Nuclear Energy Industry With Focus On Safety, Olivia Crasta, Cem Yilmaz Mar 2016

Application Of Smart Factory Design In Nuclear Energy Industry With Focus On Safety, Olivia Crasta, Cem Yilmaz

Engagement & Service-Learning Summit

No abstract provided.


A Simulation Model For Decision Support In Business Continuity Planning, Marissa Anne Mosunich Mar 2016

A Simulation Model For Decision Support In Business Continuity Planning, Marissa Anne Mosunich

Master's Theses

Enterprises with a global supply network are at risk of lost revenue as a result of disruptive disasters at supplier locations. Various strategies exist for addressing this risk, and a variety of types of research has been done regarding the identification, assessment and response to the risk of disruption in a supply chain network.

This thesis establishes a decision model to support Business Continuity Planning at the first-tier supplier level. The decision model incorporates discrete-event simulation of supply chain networks (through Simio software), Monte Carlo simulation, and risk index optimization. After modeling disruption vulnerability in a supply chain network, costs …


การพัฒนาแนวทางในการปรับยกระดับระบบบริหารคุณภาพจาก Iso 9001:2008 สู่ Iso 9001:2015, อัครพันธ์ จันทร์เสงี่ยม Jan 2016

การพัฒนาแนวทางในการปรับยกระดับระบบบริหารคุณภาพจาก Iso 9001:2008 สู่ Iso 9001:2015, อัครพันธ์ จันทร์เสงี่ยม

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้มีจุดมุ่งหมายเพื่อประยุกต์การบริหารการเปลี่ยนแปลงในการปรับเปลี่ยนระบบบริหารคุณภาพ ISO 9000 ซึ่งปัจจุบันได้มีการปรับเปลี่ยนจากระบบบริหารคุณภาพ ISO 9001:2008 มาเป็นระบบบริหารคุณภาพ ISO 9001:2015 การเปลี่ยนแปลงนี้เป็นการเปลี่ยนแปลงที่เกิดจากภายนอกองค์กร (External Change) โดยองค์กรที่ได้รับการรับรองระบบ ISO หรือองค์กรที่ต้องการต่อใบรับรองต้องดำเนินการให้เหมาะสม งานวิจัยนี้เป็นการประยุกต์ใช้ขั้นตอนเพื่อการบริหารการเปลี่ยนแปลงให้บรรลุเป้าหมาย 8 ประการ ดังนี้ 1) สร้างสำนึกความจำเป็นเร่งด่วนที่ต้องเปลี่ยนแปลง 2) สร้างขุมพลังในการนำการเปลี่ยนแปลง 3) กำหนดวิสัยทัศน์และแผนการเปลี่ยนแปลงเชิงกลยุทธ์ 4) สื่อสารวิสัยทัศน์เพื่อสร้างการสนับสนุน 5) การดำเนินการเพื่อขจัดอุปสรรคของการเปลี่ยนแปลง 6) กำหนดเป้าหมายระยะสั้น และวางแผนเพื่อให้บรรลุเป้าหมาย 7) เสริมแรงการเปลี่ยนแปลงเพื่อการพัฒนาอย่างยั่งยืน 8) ปลูกฝังสิ่งที่เปลี่ยนแปลงให้เป็นส่วนหนึ่งของวัฒนธรรมบริษัท โดยแต่ละขั้นตอนได้นำเอาแนวคิดและทฤษฎีที่เกี่ยวกับการบริหารการเปลี่ยนแปลง เช่น แนวคิดเกี่ยวกับการต้านทานการเปลี่ยนแปลง (Force Field Analysis) การทดสอบความพร้อมในการเปลี่ยนแปลง (TROPICS Test) การศึกษาสภาพแวดล้อมองค์กร การวางแผนกลยุทธ์องค์กร การประเมินความเสี่ยง เป็นต้น มาประยุกต์ใช้เพื่อให้เกิดการเปลี่ยนแปลงได้อย่างมีประสิทธิผล และในงานวิจัยนี้ยังได้นำกระบวนการบริหารการเปลี่ยนแปลงของระบบบริหารคุณภาพนี้ ไปประยุกต์ใช้กับบริษัทกรณีศึกษาบริษัทผลิตโคมไฟ ซึ่งเป็นบริษัทผลิตโคมไฟลำดับแรกๆของประเทศ โดยผลของการประยุกต์ใช้ในครั้งนี้ส่งผลให้สามารถพัฒนากรอบการบริหารการเปลี่ยนแปลงเพื่อปรับเปลี่ยนระบบบริหารคุณภาพได้อย่างมีประสิทธิภาพ


A Scalable Algorithm For Locating Distribution Centers On Real Road Networks, Saeed Ghanbartehrani, Jose D. Porter Jan 2016

A Scalable Algorithm For Locating Distribution Centers On Real Road Networks, Saeed Ghanbartehrani, Jose D. Porter

14th IMHRC Proceedings (Karlsruhe, Germany – 2016)

The median problem is a type of network location problem that aims at finding a node with the total minimum demand weighted distance to a set of demand nodes in a weighted graph. In this research, an algorithm for solving the median problem on real road networks is proposed. The proposed algorithm, referred to as the multi-threaded Dijkstra’s (MTD) algorithm, is then used to optimally locate Wal-Mart distribution centers on the 28-million node road network of the United States with the objective of minimizing the total demand weighted transportation cost. The resulting optimal location configuration of Wal-Mart distribution centers improves …


Evaluating Transaction Pairing Strategies For Vehicle-Based High-Density Storage Systems, Debjit Roy, Harit Joshie Jan 2016

Evaluating Transaction Pairing Strategies For Vehicle-Based High-Density Storage Systems, Debjit Roy, Harit Joshie

14th IMHRC Proceedings (Karlsruhe, Germany – 2016)

Vehicle-based storage and retrieval systems present an attractive choice for distribution center automation because it provides the flexibility in managing demand fluctuations without affecting transaction throughput times. In this research, we contend that while dual-command cycles can reduce the vehicle travel times for processing transactions, it may not be the best policy for reducing transaction throughput times when transactions arrive at random time instants. We develop stochastic models to test the transaction throughput time performance with multiple pairing strategies and present operational insights.


Continuous Approximation Of Multi Cycle Time For Multi Aisles Automated Storage And Retrieval Systems., Yassine Boudghene Stambouli, Latefa Ghomri Jan 2016

Continuous Approximation Of Multi Cycle Time For Multi Aisles Automated Storage And Retrieval Systems., Yassine Boudghene Stambouli, Latefa Ghomri

14th IMHRC Proceedings (Karlsruhe, Germany – 2016)

Knowing that, in an automated storage and retrieval system, the travel time of the storage/retrieval machine is an important parameter which affects the whole system performances, several works were dedicated to its evaluation and its modeling, in single, dual and multi command. These models were proposed for different configurations of AS/RS; such as unit load, multi-aisles and Mobile Racks. These models are based mainly on a discrete approach and the analytical expressions represent the system functioning exactly. In this paper we present a general approach for analytical modeling of multi command cycle time by giving particularly the modeling of the …


Outsourced Storage And Fulfillment Facility To Enhance The Service Capabilities Of Shopping Mall Tenants, Zachary Montreuil, Mike Ogle Jan 2016

Outsourced Storage And Fulfillment Facility To Enhance The Service Capabilities Of Shopping Mall Tenants, Zachary Montreuil, Mike Ogle

14th IMHRC Proceedings (Karlsruhe, Germany – 2016)

This paper proposes development of an Inventory and Fulfillment Center (IFC) that will provide a new range of outsourced, centralized storage and services for shopping mall tenants. The paper describes the competitive issues faced by shopping mall tenants, the requirements and features of a centralized, outsourced storage and fulfillment facility, and development of an agent-based model in AnyLogic® to demonstrate the concept. The range of research and business challenges introduced by this new concept are also presented.


New Design Guidelines For In-Plant Milk-Run Systems, Thorsten Schmidt, Ingolf Meinhardt, Frank Schulze Jan 2016

New Design Guidelines For In-Plant Milk-Run Systems, Thorsten Schmidt, Ingolf Meinhardt, Frank Schulze

14th IMHRC Proceedings (Karlsruhe, Germany – 2016)

Tugger trains became a popular means of supply in material handling intensive production systems. In contrast to forklift trucks they interlink a supermarket with multiple delivery locations along a transport route in a milk-run. But the efficiency gain (higher transport capacity, reduced labor costs) has its price: Compared to forklift trucks, planning and dimensioning of in-plant milk-run systems is more complicated. The paper discusses features and drawbacks of a recent standardization approach of the Association of German Engineers (VDI) and highlights the variety of technical restrictions which have to be considered when a milkrun system is designed. It shows, that …


The Storage Replenishment Problem In Rectangular Warehouses, Haldun Sural, Claudia Archetti, Melih Celik Jan 2016

The Storage Replenishment Problem In Rectangular Warehouses, Haldun Sural, Claudia Archetti, Melih Celik

14th IMHRC Proceedings (Karlsruhe, Germany – 2016)

In warehouses, storage replenishment operations involve the transportation of items to capacitated item slots in forward storage area from reserve storage. These items are later picked from these slots as their demand arises. While order picking constitutes the majority of warehouse operating costs, replenishment operations might be as costly in warehouses where pick lists generally consist of only a few lines (e.g., order fulfillment warehouses). In this study, we consider the storage replenishment problem in a parallel-aisle warehouse, where replenishment and order picking operations are carried out in successive waves with time limits. The aim is to determine the item …


Performance Comparison Of Automated Warehouses Using Simulation, Nand Kishore Agrawal, Sunderesh S. Heragu, Chinnatat Methapatra Jan 2016

Performance Comparison Of Automated Warehouses Using Simulation, Nand Kishore Agrawal, Sunderesh S. Heragu, Chinnatat Methapatra

14th IMHRC Proceedings (Karlsruhe, Germany – 2016)

The purpose of this study is to compare the performance of two types of warehouses, both of which use autonomous vehicles (AVs). One warehouse uses movable racks (MR) for storing mini-loads, whereas the other uses fixed racks (FR). In general, warehouse automation not only increases the speed of the fulfillment process but also makes the picking process more accurate. We simulate three scenarios for the MR and FR systems using Simio. Four performance measures are considered for the comparison – the average order processing time (WR), the average utilization of AVs (U), the average order processing queue length (Nq) and …


Job Sequencing In A Miniload System, Lennart Baardman, Kees Jan Roodbergen Jan 2016

Job Sequencing In A Miniload System, Lennart Baardman, Kees Jan Roodbergen

14th IMHRC Proceedings (Karlsruhe, Germany – 2016)

More and more warehouses shift towards the use of automated systems. One such system is a miniload system. In this system, a crane retrieves bins from their storage locations and brings the bins to the picking station, where a worker takes the requested products from the retrieved bins. After a product has been picked, the bin is put back by the crane in its original location. A buffer is present at the picking station to absorb fluctuations in speed between the picker and the crane. The problem of scheduling jobs in this system has received little attention in the literature. …


Dual-Tray Vertical Lift Modules For Fast Order Picking, Daria Battini, Martina Calzavara, Alessandro Persona, Fabio Sgarbossa Jan 2016

Dual-Tray Vertical Lift Modules For Fast Order Picking, Daria Battini, Martina Calzavara, Alessandro Persona, Fabio Sgarbossa

14th IMHRC Proceedings (Karlsruhe, Germany – 2016)

In the last years, new solutions for order picking systems have been developed both from industry and academics, especially for small items. They include innovative flexible automatic parts-to-picker systems and optimized picker-to-parts ones. One of these solutions consists in the use of Vertical Lift Modules (VLMs), a storage column in which small items are stored in extractable trays. In this paper, we study a new system composed by dual-tray VLMs where the operators perform picking and sorting activities. We propose several actions in order to improve the productivity of the entire system: 1) class based storage assignment of items inside …


Throughput Rate Of A Two-Worker Stochastic Bucket Brigade, Yossi Bukchin, Eran Hanany, Eugene Khmelnitsky Jan 2016

Throughput Rate Of A Two-Worker Stochastic Bucket Brigade, Yossi Bukchin, Eran Hanany, Eugene Khmelnitsky

14th IMHRC Proceedings (Karlsruhe, Germany – 2016)

Work-sharing in production systems is a modern approach that improves throughput rate. Work is shifted between cross-trained workers in order to better balance the material now in the system. When a serial system is concerned, a common work-sharing approach is the Bucket-Brigade (BB), by which downstream workers sequentially take over items from adjacent upstream work- ers. When the workers are located from slowest-to-fastest and their speeds are deterministic, it is known that the line does not suffer from blockage or starvation, and achieves the maximal theoretical throughput rate (TR). Very little is known in the literature on stochastic self-balancing systems …


A Performance Measurement Framework And Solution Approach For The Integrated Facility Layout Problem With Uncertain Demand, Melih Celik, Begun Efeoglu, Haldun Sural Jan 2016

A Performance Measurement Framework And Solution Approach For The Integrated Facility Layout Problem With Uncertain Demand, Melih Celik, Begun Efeoglu, Haldun Sural

14th IMHRC Proceedings (Karlsruhe, Germany – 2016)

The integrated facility layout problem (IFLP) focuses on the simultaneous determination of the relative locations of multiple copies of capacitated equip- ment or machinery in a facility, as well as the material ow between these units. In this paper, we consider the IFLP in the existence of uncertain demand for the products of the facility. Motivated by the framework for next generation facility layouts by Benjaafar et al. (2002), we extend the approaches in the lit- erature for distributed facility layouts to the case of dynamic demand and the possibility of relayouts, and propose a heuristic solution approach to minimize …


Transport Items And Physical Internet Handling Boxes: A Comparison Framework Across Supply Chains, Eric Ballot, Benoit Montreuil Jan 2016

Transport Items And Physical Internet Handling Boxes: A Comparison Framework Across Supply Chains, Eric Ballot, Benoit Montreuil

14th IMHRC Proceedings (Karlsruhe, Germany – 2016)

Pallets, cardboard boxes, and plastic crates are widely used tools to operate supply chains. As such they have many impacts on handling effort, shipment protection, transport mean utilization as well as repositioning and recycling efforts and they represent billions of assets spread all over the world. The historical and local origins of the designs and the sharing among many stakeholders do not ensure at all any kind of global optimization. The purpose of this paper is to define and explain a research effort to better measure and evaluate the efficiencies and inefficiencies for supply chain stakeholders for themselves and globally. …


Energy And Cycle Time Efficient Warehouse Design For Autonomous Vehicle-Based Storage And Retrieval System, Banu Yetkin Ekren, Tone Lerher Jan 2016

Energy And Cycle Time Efficient Warehouse Design For Autonomous Vehicle-Based Storage And Retrieval System, Banu Yetkin Ekren, Tone Lerher

14th IMHRC Proceedings (Karlsruhe, Germany – 2016)

This study explores the best warehouse design for an autonomous vehicle based storage and retrieval system (AVS/RS) minimizing average energy consumption per transaction and average cycle time per transaction, simultaneously. In the design concept, we consider, rack design in terms of number of bays, number of tiers, number of aisles; number of resources, namely number of autonomous vehicles and lifts and; velocity profiles of lifts and autonomous vehicles in the AVS/RS. We completed 1,296 number of experiments in simulation to obtain Pareto solutions representing the “average energy consumption per transaction” and “average cycle time per transaction” trade-offs based on designs …


Determination Of Cycle Times For Double Deep Storage Systems Using A Dual Capacity Handling Device, Katharina Dorr Jan 2016

Determination Of Cycle Times For Double Deep Storage Systems Using A Dual Capacity Handling Device, Katharina Dorr

14th IMHRC Proceedings (Karlsruhe, Germany – 2016)

Double deep storage is an efficient method to improve space utilization in warehouses. Contrary to intuition, it also can be efficient when considering retrieval times, since the aisles of a warehouse with double deep storage may be shorter than comparable warehouses with single deep storage. AS/RS-machines equipped with two load-handling units might further improve the situation, since two storage units (for instance pallets or cases) can be stored and retrieved, effectively allowing quadruple command cycles, bringing in total two storage units into the aisle and retrieving two storage units at the same time. In this paper, we present a method …


A Simulation Model To Evaluate The Layout For Block Stacking Warehouses, Shahab Derhami, Jeffrey S. Smith, Kevin R. Gue Jan 2016

A Simulation Model To Evaluate The Layout For Block Stacking Warehouses, Shahab Derhami, Jeffrey S. Smith, Kevin R. Gue

14th IMHRC Proceedings (Karlsruhe, Germany – 2016)

Storing pallets of Stock Keeping Units (SKU's) on top of another in lanes on a warehouse floor is known as block stacking. This storage system is widely used in manufactoring systems and distribution centers. The arrangement of lanes in the layout of this system significantly impacts utilization of the storage space and transportation costs. Existing research that studies the layout for this system focuses exclusively on determining the optimal lane depth with respect to space utilization and ignores transportation costs. In this study, we develop a stimulation model that computes several performance metrics to evaluate both of these objectives for …


A Novel Approach To Analyze Inventory Allocation Decisions In Robotic Mobile Fulfillment Systems, Tim Lamballais, Debjit Roy, M.B.M De Koster Jan 2016

A Novel Approach To Analyze Inventory Allocation Decisions In Robotic Mobile Fulfillment Systems, Tim Lamballais, Debjit Roy, M.B.M De Koster

14th IMHRC Proceedings (Karlsruhe, Germany – 2016)

The Robotic Mobile Fulfillment System is a newly developed automated, parts-to-picker material handling system. Storage shelves, also known as inventory pods, are moved by robots between the storage area and the workstations, which means that they can be continually repositioned during operations. This paper develops a queueing model for optimizing three key decision variables: (1) the number of pods per product (2) the ratio of the number of pick to the number of replenishment stations, and (3) the replenishment level per pod. We show that too few or too many pods per product leads to unnecessarily long order throughput times, …