Dynamic Modelling of an Automated Vehicle Storage and Retrieval System and a Simulation Analysis of its Efficiency

In this paper operating-time models for single and multiple instructions are set up considering an AVS/RS (automated vehicle storage and retrieval system). The operation times of AVS/RS and AS/RS (automated storage and retrieval system) are simulated in different situations by changing the shelf structure and order density. The results show that the AVS/RS is more efficient than the AS/RS in all situations. Furthermore, the numbers of rows and columns of storage shelves greatly influence the operation time. The graph of operation-time compression ratio against number of columns shows an inverted U-type distribution, and the compression ratio decreases and ultimately tends to zero as the number of rows is increased. Also, the order density affects the efficiency difference between the two systems: the higher the order density, the higher the AVS/RS operating-time compression rate. Finally, compared with the AS/RS, the AVS/RS operating-time compression ratio improves greatly with increasing density and number of rows because of parallel operations, whereas with decreasing density and number of rows the AVS/RS advantages are gradually lost and the compression ratio decreases and eventually even reaches zero

Penerapan Six Sigma Untuk Perbaikan Masalah Kepadatan Dan Kemacetan Workstation Gudang Ekspor Di Perusahaan Cargo Handling Bandara Soekarno Hatta

Pengangkutan kargo melalui pesawat udara merupakan salah satu rantai distribusi barang yang memerlukan biaya dan juga standar keselamatan yang tinggi. PT Jasa Angkasa Semesta (JAS) merupakan salah satu perusahaan ground handling di Bandara Internasional Soekarno Hatta yang salah satu unit usahanya adalah penanganan kargo di gudang ekspor. Salah satu proses di gudang ekspor adalah proses menaikkan kargo ke dalam Unit Load Device (ULD) atau biasa disebut proses build up yang dilakukan di workstation. Kepadatan dan kemacetan sering terjadi di workstation dan akibatnya proses build up, proses penimbangan, pelaporan dan penarikan kargo ke pesawat menjadi terhambat. Penelitian terhadap kepadatan dan kemacetan di workstation bertujuan untuk memecahkan masalah di workstation. Penelitian ini menggunakan metode six sigma DMAIC (Define, Measure, Analyze, Improve dan Control) untuk memecahkan masalah. Dalam tahap define dimulai dengan membuat project charter dan menentukan tim yang akan terlibat. Pada tahap measure menunjukkan bahwa level sigma pada workstation berada pada σ = 3.18. Analisis dilakukan dengan menggunakan metode fishbone dan menunjukkan bahwa penyebab utama dari masalah kepadatan dan kemacetan adalah kapasitas workstation dan penjadwalan build up. Untuk tahap improvement dilakukan dengan melakukan brain storming untuk melakukan perbaikan dan control dilakukan untuk memastikan bahwa improvement yang dibuat akan selalu sesuai harapan. Hasil penerapan penjadwalan, dengan perbandingan hari ke hari, kepadatan dapat berkurang sebesar 28% dan hasil perbaikan penurunan defect sebesar 8.7%. ======================================================================================================== Air cargo transportation is one of goods distribution with high cost and high safety standard. PT Jasa Angkasa Semesta (JAS) is one of ground handling company in Soekarno Hatta International Airport where one of its businesses is cargo handling in export warehouse. One of the processes in the export warehouse is loading cargo into Unit Load Device (ULD) or build up in the workstation. Bottleneck often occurs in the workstation and it affects the build up process, weighing process, reporting, and cargo towing to the aircraft is late. The research was aiming to solve the problem in the workstation. The research used six Sigma DMAIC (Define, Measure, Analyze, Improve, and Control) methodologies to solve the problem. The define phase roll out the project charter and the team involved. On the measure phase reveals that the sigma level of the workstation was on σ = 3.18. The analysis was conducted using fishbone method and the main causes of the bottleneck were capacity and build up scheduling. On improve phase, brain storming was carried out to solve the issue and capability analysis was made to make sure no recurrence on suggested improvement. The result of Build up scheduling implementation reduced congestion by 28% and yield improvement 8.7%

Joint scheduling of material handling equipment in automated air cargo terminals

This paper develops a joint approach to solve the problem of integrated scheduling of different types of material handling equipment in a typical automated air cargo handling system. Due to the nature of the operations, the schedules for different cooperating equipment are highly interactive. In order to formally describe the interactive properties of cooperating equipment, an event framework for the specification of an automated cargo handling system and a model for the integrated scheduling for more than one type of cooperating equipment is developed. A heuristic algorithm, known as the extended maximum-matching algorithm (EMMA), is proposed to solve the joint scheduling problem. The performance of the proposed EMMA is evaluated via extensive numerical studies. Experimental results show that the EMMA can be readily adapted to real-world applications. © 2006 Elsevier B.V. All rights reserved.link_to_subscribed_fulltex

Multikriterielle Ablaufplanung und -steuerung in dynamischen und stochastischen Umgebungen : Ein Beitrag zur Erstellung robuster Ablaufpläne für die Frachtabfertigung in Luftfrachtterminals

Luftfrachtterminals stellen die zentrale Schnittstelle für den Umschlag von Fracht in der Luftfrachttransportkette dar. Ein stetiges Wachstum des globalen Luftfrachtbedarfs in Kombination mit steigenden Sicherheitsanforderungen stellt die Frachtabfertigung innerhalb der kapazitativ beschränkten Terminals vor neue Herausforderungen. Eine effiziente Ablaufplanung und -steuerung der Frachtabfertigungsaufträge ist daher essenziell, um die Fracht mit der für den Kunden gewohnten Servicequalität zu bearbeiten. In der vorliegenden Arbeit wird ein Ablaufplanungs- und -steuerungssystem in Form einer Architektur umgesetzt, das eine proaktiv-reaktive Ablaufplanung ermöglicht und dabei die dynamische und stochastische Systemumgebung berücksichtigt. Die rollierende proaktive Ablaufplanung stellt das zentrale Element der Architektur dar. Diese dient der Erstellung robuster Ablaufpläne, die eine Immunisierung gegenüber stochastischen Bearbeitungszeiten der Frachtabfertigungsaufträge gewährleisten. Grundlage für die Quantifizierung der Bearbeitungszeitunsicherheiten neuer Aufträge stellen Informationen über historische Abfertigungsaufträge dar, aus denen ein Informationsstand abgeleitet wird. Dieses Vorgehen gewährleistet die kontinuierliche Adaption der Ablaufplanung an sich ändernde Prozessunsicherheiten bei der Bearbeitung von Fracht. Ergänzend werden reaktive Maßnahmen im Rahmen der Ablaufsteuerung aufgezeigt, die eine ereignisorientierte Revision des aktiven Ablaufplans ermöglichen. Die erstellte Architektur wird anhand realer und synthetischer Testinstanzen validiert. Die Validierungsergebnisse zeigen, dass der vorgestellte Ansatz ein effektives Konzept darstellt, um die Robustheit erstellter Ablaufpläne zu erhöhen und die Ablaufplanung automatisiert an bestehende Prozessunsicherheiten anzupassen.Air cargo terminals represent the major interface in the air freight transport chain for the transshipment of freight. A continuous growth of the global demand for air freight combined with increased safety requirements pose new challenges to the freight handling within the capacity restricted terminals. Therefore, an efficient scheduling and control of the freight handling jobs is essential for handling the freight with the service quality the customer is used to. In the present work a scheduling and control system in the form of an architecture is developed that enables a proactive-reactive scheduling considering the dynamic and stochastic system environment. The rolling proactive scheduling represents the central element of the architecture. It is used to create robust schedules, which ensure the immunization against stochastic processing times of the freight handling jobs. The basis to quantify the processing time uncertainties of new jobs are information about historical freight handling jobs, from which an information base is derived. This approach ensures the continuous adaptation of the scheduling system to changing process uncertainties of the freight handling jobs. Additionally, reactive methods for the sequence control are illustrated that enable an event-oriented revision of the active schedule. The developed architecture is validated on real and synthetic test instances. The validation results show the effectiveness of the presented approach to increase the robustness of created schedules and to automatically adapt the scheduling process to existing process uncertainties.von Simon Boxnick, M. Sc. ; Dekanin: Prof. Dr. Caren Sureth-Sloane, Referent: Prof. Dr.-Ing. habil. Wilhelm Dangelmaier, Korreferentin: Prof. Dr. Leena SuhlTag der Verteidigung: 10.05.2016Universität Paderborn, Fakultät für Wirtschaftswissenschaften, Univ., Dissertation, 201

Gestión del conocimiento. Perspectiva multidisciplinaria. Volumen 17

El libro “Gestión del Conocimiento. Perspectiva Multidisciplinaria”, Volumen 17 de la Colección Unión Global, es resultado de investigaciones. Los capítulos del libro, son resultados de investigaciones desarrolladas por sus autores. El libro es una publicación internacional, seriada, continua, arbitrada, de acceso abierto a todas las áreas del conocimiento, orientada a contribuir con procesos de gestión del conocimiento científico, tecnológico y humanístico. Con esta colección, se aspira contribuir con el cultivo, la comprensión, la recopilación y la apropiación social del conocimiento en cuanto a patrimonio intangible de la humanidad, con el propósito de hacer aportes con la transformación de las relaciones socioculturales que sustentan la construcción social de los saberes y su reconocimiento como bien público