Relocation and Storage Assignment Strategies Evaluation in a Multiple-deep Tier-captive Automated Vehicles Storage and Retrieval System with Undetermined Retrieval Sequence

2021 ◽  
Author(s):  
Jakob Marolt ◽  
Nenad Kosanić ◽  
Tone Lerher
Keyword(s):  
Retrieval System ◽  
Discrete Event ◽  
Nearest Neighbour ◽  
Throughput Performance ◽  
Storage And Retrieval ◽  
Event Simulation ◽  
Retrieval Systems ◽  
Storage Assignment ◽  
And Storage

Abstract This paper studies multiple-deep automated vehicle storage and retrieval systems (AVS/RS) known for their high throughput performance and flexibility. Compared to a single-deep system, multiple-deep AVS/RS has a better space area utilisation. However, a relocation cycle occurs, reducing the throughput performance whenever another stock-keeping unit (SKU) blocks a retrieving SKU. The SKU retrieval sequence is undetermined, meaning that the arrangement is unknown, and all SKUs have an equal probability of retrieval. In addition to the shuttle carrier, a satellite vehicle is attached to the shuttle carrier and is used to access storage locations in multiple depths. A discrete event simulation of multiple-deep AVS/RS with a tier captive shuttle carrier was developed. We focused on the dual command cycle time assessment of nine different storage and relocation assignment strategies combinations in the simulation model. The results of a simulation study for (i) Random, (ii) Depth-first and (iii) Nearest neighbour storage and relocation assignment strategies combinations are examined and benchmarked for five different AVS/RS case study configurations with the same number of storage locations. The results display that the fivefold and sixfold deep AVS/RS outperform systems with fewer depths by utilising Depth-first storage and Nearest neighbour relocation assignment strategies.

scholarly journals An approach for performance evaluation of SBS/RS with shuttle vehicles serving multiple tiers of multiple-deep storage rack

2020 ◽  
Vol 110 (11-12) ◽  
pp. 3241-3256
Author(s):  
Michael Eder
Keyword(s):  
Material Handling ◽  
Queueing System ◽  
Discrete Event ◽  
Calculation Model ◽  
Limited Capacity ◽  
Operating Characteristics ◽  
Cycle Times ◽  
Storage And Retrieval ◽  
Event Simulation ◽  
Retrieval Systems

Abstract This paper presents a method for determining the performance of shuttle-based storage and retrieval systems (SBS/RS) with tier-captive, single-aisle shuttles serving various numbers of tiers of multiple-deep storage. The use of this approach takes place in the design process of SBS/RS. The proposed approach considers the real operating characteristics of the shuttle and lifts. The basis of this calculation method is a continuous-time, open-queueing system with limited capacity. The cycle times of the lifts and shuttles, determined by a spatial value approach, can be used directly in the presented method with an assumed uniform distribution of storage locations and a probability-based model of storage depth. This approach is validated by a comparison with a discrete-event simulation. Finally, an example based on a system provided by a European material handling provider is presented to outline how this calculation model can be used for designing SBS/RS that fulfill predefined requirements. The result of this example is a decrease in the needed ground space with an increasing number of tiers served by each shuttle and with increasing storage depth.

Improving Casthouse Throughput Using Discrete-Event Modelling

2011 ◽  
Vol 693 ◽  
pp. 3-9 ◽  
Author(s):  
Bruce Gunn ◽  
Yakov Frayman
Keyword(s):  
Sensitivity Analysis ◽  
Discrete Event ◽  
Casting Machine ◽  
Production Data ◽  
Model Output ◽  
Arrival Times ◽  
Event Simulation ◽  
Modelling System ◽  
Key Parameter

The scheduling of metal to different casters in a casthouse is a complicated problem, attempting to find the balance between pot-line, crucible carrier, furnace and casting machine capacity. In this paper, a description will be given of a casthouse modelling system designed to test different scenarios for casthouse design and operation. Using discrete-event simulation, the casthouse model incorporates variable arrival times of metal carriers, crucible movements, caster operation and furnace conditions. Each part of the system is individually modelled and synchronised using a series of signals or semaphores. In addition, an easy to operate user interface allows for the modification of key parameters, and analysis of model output. Results from the model will be presented for a case study, which highlights the effect different parameters have on overall casthouse performance. The case study uses past production data from a casthouse to validate the model outputs, with the aim to perform a sensitivity analysis on the overall system. Along with metal preparation times and caster strip-down/setup, the temperature evolution within the furnaces is one key parameter in determining casthouse performance.

Development of Automatic Storage Retrieval System for Variable Loads

2021 ◽  
Vol 18 (1) ◽  
pp. 99
Author(s):  
Afzeri Tamsir
Keyword(s):  
Data Storage ◽  
Integrated System ◽  
Numerical Control ◽  
Storage And Retrieval ◽  
Retrieval Systems ◽  
Speed Up ◽  
Automated Storage ◽  
Warehousing Systems ◽  
And Storage ◽  
Carrier Element

 Automated Storage and Retrieval Systems (ASRS) have been widely used in warehousing systems to speed up load movements and save storage space. ASRS is an integrated system that is equipped with a controller and arm for the collection and storage of goods. This paper discusses the results of developing a system for taking and storing goods for various loads. The prototype element consists of a mechanism for retrieving, placing and application for data collection into the database. In this research, the design and development of ASRS was carried out to be applied in the storage of products of various sizes which is suitable for small size industries. The development process includes investigating features that have been developed in the ASRS, operating procedures, hardware selection and software development in accordance with the mechanism designed. Numerical control which moves the carrier element with high resolution is applied to be able to place the load in a changing position. Development and testing is carried out to ensure the performance of the tool runs well and the data storage that includes the identification and size of the load can be recorded properly.

Applying Discrete Event Simulation (DES) in Healthcare

2015 ◽  
pp. 390-410
Author(s):  
Stavros T. Ponis ◽  
Angelos Delis ◽  
Sotiris P. Gayialis ◽  
Panagiotis Kasimatis ◽  
Joseph Tan
Keyword(s):  
Discrete Event Simulation ◽  
Capacity Planning ◽  
Planning Process ◽  
Discrete Event ◽  
Healthcare Facilities ◽  
Performance Improvements ◽  
Event Simulation ◽  
Health Insurance Provider ◽  
And Performance

This paper highlights the opportunities and challenges of applying Discrete Event Simulation (DES) to support capacity planning of a network of outpatient facilities. Despite an abundance of studies using simulation techniques to examine the operation and performance of outpatient clinics, the problem of capacity allocation and planning of medical services within a network of outpatient healthcare facilities appears to be underexplored. Here, a case study of a health insurance provider that operates a network of six outpatient medical facilities in the US is used to illustrate and explore the synthesizing and adaptive, yet parsimonious nature of using DES methodology for network design and capacity planning. Results of this case study demonstrate that significant performance improvements for the network operator can be achieved with applying DES method to support the network facility capacity planning process.

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