35 research outputs found
An overview for food loss and waste reduction in food supply chains
Creating systems designs by considering a balance between economic, environmental and social effects is significant in today’s sustainability concern. Sustainability has become an emerging topic, growing concerns and attention for companies. Especially companies operating on a global scale aim to develop strategies for sustainable supply chain management. When the supply chain is a food chain, that concern increases exponentially and sustainable management of the chain becomes a critical challenge requiring the development and implementation of innovative practices by all stages within value chains. According to the Food and Agriculture Organization (FAO) one-third of all food produced in the world is lost or wasted from farm to fork. This waste has great negative impact on global economy, food availability, as well as environment. In this work, we focus on food loss and waste subject by searching how they could be reduced in throughout a supply chain network. We provide solution ways for the food waste/loss reduction obtained from current works in literature
A reinforcement learning approach for transaction scheduling in a shuttle-based storage and retrieval system
With recent Industry 4.0 developments, companies tend to automate their industries. Warehousing companies also take part in this trend. A shuttle-based storage and retrieval system (SBS/RS) is an automated storage and retrieval system technology experiencing recent drastic market growth. This technology is mostly utilized in large distribution centers processing mini-loads. With the recent increase in e-commerce practices, fast delivery requirements with low volume orders have increased. SBS/RS provides ultrahigh-speed load handling due to having an excess amount of shuttles in the system. However, not only the physical design of an automated warehousing technology but also the design of operational system policies would help with fast handling targets. In this work, in an effort to increase the performance of an SBS/RS, we apply a machine learning (ML) (i.e., Q-learning) approach on a newly proposed tier-to-tier SBS/RS design, redesigned from a traditional tier-captive SBS/RS. The novelty of this paper is twofold: First, we propose a novel SBS/RS design where shuttles can travel between tiers in the system; second, due to the complexity of operation of shuttles in that newly proposed design, we implement an ML-based algorithm for transaction selection in that system. The ML-based solution is compared with traditional scheduling approaches: first-in-first-out and shortest process time (i.e., travel) scheduling rules. The results indicate that in most cases, the Q-learning approach performs better than the two static scheduling approaches
Experimental Validation of Travel Time Models for Shuttle-based Automated Storage and Retrieval System
In this paper, we aim to validate travel time models for single and dual command cycle displacements of lifts and shuttles in a shuttle-based automated storage and retrieval system (SBS/RS) by using experimental computer simulation. The models under consideration take into account acceleration and deceleration delays. We use ARENA 12 software for the simulation modeling. By simulation, we emulate the real functioning of the system. Therefore, we assume that the results from the ARENA simulation are equivalent to the onsite experimentation. Simulation results are very close to those obtained by analytical travel time models. This shows the high precision of these models to predict operations of SBS/RS.These models can be used at design or operation phases to calculate throughput of the system, to compare between different topologies of SBS/RS or with other types of AS/RS to help decision makers to choose among different alternatives of automated storage systems
Shuttle-based storage and retrieval systems designs from multi-objective perspectives: total investment cost, throughput rate and sustainability
This paper studies performance comparison of two shuttle-based storage and retrieval system (SBS/RS) configurations developed on flexible or non-flexible travel policies of shuttles in the system. In the non-flexible SBS/RS, a shuttle is dedicated to a tier so that it cannot travel out of its dedicated aisle and tier. A lifting mechanism is installed in each aisle to provide vertical travel for loads. In flexible SBS/RS, shuttles can travel between tiers by a separate lifting mechanism installed on the other edge point of each aisle. The advantage of that flexible design is that there might be decreased number of shuttles settling in the system compared to the non-flexible design. We simulate the two system configurations and conduct an experimental design for the comparison purpose. Based on the three-performance metrics: total investment cost, throughput rate and energy consumption per transaction, the results show that mainly the flexible system provides better results which might be considered as future system investment for SBS/RS
Simulation-based Performance Improvement of a Defense Logistics Warehouse
Warehouses play a critical role in supply chains. They serve as a vital link between manufacturers and customers. In this study, we investigate performance of the largest warehouse (Eastern Distribution Center - EDC) of the Defense Logistics Agency (DLA) located in New Cumberland, PA and propose a near optimum design for the receiving area of the warehouse to improve its performance. First, we develop a simulation model of the system. Second, we interface an optimization model with the simulation in order to optimize the number of people working at the induction stations. In the optimization model, our goal is to minimize the average cycle time of a material type. Last, we re-design the existing system based on results from the optimization. The simulation and the optimization models are developed through the use of ARENA 13.9 and Opt Quest
Multi-objective optimisation model of shuttle-based storage and retrieval system
This paper presents a multi-objective optimisation solution procedure for the design of the Shuttle-Based Storage and Retrieval System (SBS/RS). An efficient SBS/RS design should take into account multi-objectives for optimization. In this study, we considered three objective functions in the design concept which are the minimization of average cycle time of transactions (average throughput time), amount of energy (electricity) consumption and total investment cost. By also considering the amount of energy consumption as an objective function for minimization, we aimed to contribute to an environmentally friendly design concept. During the optimization procedure, we considered seven design variables as number of aisles, number of tiers, number of columns, velocities of shuttle carriers, acceleration/deceleration of shuttle carriers, velocity of the elevators lifting tables and acceleration/deceleration of the elevators lifting tables. Due to the non-linear property of the objective function, we utilized the Non-Dominated Sorting Genetic Algorithm II (NSGA II) genetic algorithm for facilitating the solution. Lastly, we searched Pareto optimal solutions to find out the optimum results. We believe that this study provides a useful and a flexible tool for warehouse planners and designers, while choosing a particular type of SBS/RS at the early stage of the warehouse design.
First published online: 12 May 201
Omni-chanel network design towards circular economy under inventory share policies
In this paper, we study inventory share policies in an omni-channel supply network, to contribute to the circular economy (CE) concept. Lateral inventory share implementation provides flexibility and profitability in the supply chain by allowing inventory share between the same echelon locations in a network. Total holding costs and transportation costs can be reduced by lateral inventory share applications, which also contribute to decreased material usage for production over time, as well as reduced CO2 emission released by transportation. Technological and Internet of Things (IoT) developments make it possible for companies to share their real-time information with each other for uninterrupted marketing experiences. With such a connected network, companies aim to increase their profitability and responsiveness to their customers. We explore a well-designed inventory share policy towards the CE concept under an (s, S) inventory control policy. We simulate several pre-defined share designs by Arena 16.0 commercial software and compare their performances in terms of cost, responsiveness, transportation frequency, inventory held, etc. The results show that, by the implementation of a well-designed lateral inventory share policy, an omni-channel network can benefit from decreased holding cost and transportation cost, contributing to the CE concept
Method for evaluating the throughput performance of shuttle based storage and retrieval systems
U ovom radu prezentira se metoda proračuna protočne performanse skladišnih sustava sa shuttle-ovima/vozilima (eng. SBS/RS). SBS/RS zastupaju novu tehnologiju automatiziranih skladišnih sustava. S obzirom na važnost ispravnog oblikovanja (projektiranja) SBS/RS sustava "od prve" zbog relativne nefleksibilnosti fizičke izvedbe, prezentira se predložena metoda proračuna protočne performanse takvih sustava. Performansa sustava razmatra se kao protočni kapacitet SBS/RS kao cjeline.In this paper a method for throughput performance calculation of shuttle based storage and retrieval systems (SBS/RS) is presented. SBS/RS represent a new technology in automated storage and retrieval systems. Since it is important to design SBS/RS right the first time due to the relative inflexibility of the physical layout, we provide a proposed method for the throughput performance calculation of these systems. The performance of the system is considered as a throughput capacity of the SBS/RS as a whole
Enhancing e-grocery order fulfillment: improving product availability, cost, and emissions in last-mile delivery
This paper studies e-grocery order fulfillment policies by leveraging both customer and e-grocery-based data. Through the utilization of historical purchase data, product popularity trends, and delivery patterns, allocation strategies are informed to optimize performance metrics such as fill rate, carbon emissions, and cost per order. The study aims to conduct a sensitivity analysis to identify key drivers influencing these performance metrics. The results highlight that fulfillment policies optimized with the utilization of the mentioned data metrics demonstrate superior performance compared to policies not informed by data. These findings underscore the critical role of integrating data-driven models in e-grocery order fulfillment. Based on the outcomes, a grocery allocation policy, considering both proximity and product availability, emerges as promising for simultaneous improvements in several performance metrics. The study recommends that e-grocery companies leverage customer data to design and optimize delivery-oriented policies and strategies. To ensure adaptability to new trends or changes in delivery patterns, continual evaluation and improvement of e-grocery fulfillment policies are emphasized
Identifying the drivers of circular food packaging: a comprehensive review for the current state of the food supply chain to be sustainable and circular
The resilience of food systems is jeopardized by using food packaging materials that have adverse impacts on the environment, food quality, food safety, shelf-life, food loss, and waste. Therefore, a transition into a more sustainable system can only be possible by adopting circular economy principles and practices that can facilitate the elimination of unsustainable packaging, irresponsible disposal behaviors, and waste management. This paper mainly focuses on circular packaging practices in the existing literature to reveal the drivers of circular food packaging applications. The study also displays the triple combinations of material-sector, material-CE, and sector-CE principles. As a methodology, a systematic literature review (SLR) has been used for this study. Furthermore, this study investigates the literature findings, such as the most frequently mentioned food sector and sub-sector, CE principles, materials adopted for food packaging, and so on. The primary contribution of this study to the body of literature is the synthesis and mapping of the literature as a whole from the perspectives of CE principles, both sector-based and national, and the materials used through circular food packaging, and the attempt to facilitate this transition into a more circular system by outlining the drivers of circular food packaging