1,721,011 research outputs found
An innovative traceability system for material flows in industrial plants
No full textPurpose
The article is centred on the analysis of internal flow traceability of products within indoor environments. The purpose of the paper is to provide an innovative automatic solution for the traceability of everything that moves within industrial plants, in order to simplify and improve the process of logistics flow traceability and optimisation.
Design/Methodology/Approach
In order to analyse the traceability of material flows within indoor environments, the authors have developed an experimental research consisting in a prototype development based on a Radio Frequency IDentification (RFID) system using Ultra Wind Band (UWB) technology. The authors have realised several tests (static and dynamic) that trace the positions (static) and map the movements (dynamic) of products within indoor environments in continuous and in real-time. .
Originality/Value
The paper presents an innovative automatic traceability system for the optimal determination and measurement of the positions and paths travelled by products within industrial plants. The traceability system described in the paper is able to quickly provide the measurement (i.e. positions and paths) with a high level of accuracy and precision in a continuous manner and not only collecting several gates crossing
Biogas Micro-Production from Human Organic Waste - A Research Proposal
Full text linkOrganic waste (OW) management tackles the problem of sanitation and hygiene in developing countries and humanitarian camps where unmanaged waste often causes severe health problems and premature death. OW still has a usable energy content, allowing biogas production, potentially contributing to satisfy the local needs, e.g., cooking, lighting and heating. Digesters are the devices converting OW into biogas under anaerobic conditions. They are simple and effective solutions for the OW management in rural areas, humanitarian camps and remote developing regions, producing energy and fertilizers for local farming as residual. This paper describes the design and lab-test of a domestic OW management system integrating a waterless toilet with a small-scale digester producing safe biogas for local micro-consumption. Starting from people’s needs and an extensive review of the current state-of-art technology, the proposed system’s key innovation and strength is the combination of effectiveness and a very simple construction, set up and use, fitting with the rural conditions and raw materials available within the emerging countries. A small-scale prototype is assembled and lab-tested assessing the quantity—i.e., productivity—and quality—i.e., composition and methane content—of the produced biogas. The measured productivity in terms of specific biogas production (SBP) is of about 0.15 m3/kgSV and a methane content of about 74% in mass match the energy needs of domestic users, encouraging the spread of such systems in developing regions and rural areas
Design and simulation of assembly line feeding systems in the automotive sector using supermarket, kanbans and tow trains: a general framework
Full text linkA growing number of manufacturers are adopting the so-called supermarket strategy to supply components to the production system. Supermarkets are decentralized storage areas used as intermediate warehouses for parts required by the production system (typically assembly lines). Such a feeding system is widely used in the automotive industry where assembly stations in multiple mixed-model assembly lines are usually refilled by means of a systematic part replenishment driven by Kanban systems, adopting small trucking vehicles towing some wagons (tow trains). The aim of this paper is to provide a simple but robust framework in order to design the supermarket/feeding system dedicated to complex multiple mixed-model assembly lines. This framework proposes an integrated approach both for long-term (static analytical model) and short-term (dynamic simulation) problems dealing with Kanban and Supermarket systems dedicated to assembly lines, and the tow train fleet sizing and management. This proposed methodology is applied to a case study derived from the Italian automotive industry, and the results highlight the high interrelation between the long and the short term variables that can be evaluated only by an integrated approach that considers both static and dynamic aspects of the problem. The results of this study are then presented and widely discussed
The Use of Radio Frequency Identification Technology in Packaging Systems: Experimental Research on Traceability
Full text linkTraditionally, the traceability system is performed through the asynchronous fulfilment of checkpoints (i.e. doorways) by materials. In such cases, the tracking is manual, executed by operators that manually trace the path. Often, companies are not aware of the inefficiencies because of these traceability systems such as low precision and accuracy in measurements (i.e. no information between doorways), more time spent by operators and costs (due to the full effort of operators who have to search for the good positions and movements). In order to overcome these limitations, automatic identification procedures have been introduced in many service industries, purchasing and distribution logistics, manufacturing companies and material flow systems. Automatic identification procedures can also be applied to the packaging of products, instead of to each item contained in the package. Sometimes, products are very expensive, and packages contain important and critical goods (e.g. dangerous or explosive materials); thus, the tracking of goods – and packages in particular – is a critical function.
In order to analyse the traceability of the packaging system, the authors have developed an innovative system based on Radio Frequency IDentification-Ultra Wide Band (RFID-UWB) technology. A prototype of this system has been realized and used for an experimental research that has consisted of several tests (static and dynamic), tracing the position (static) and movements (dynamic) of products and in particular packages in indoor environments, in continuous and in real time. Copyright © 2013 John Wiley & Sons, Ltd
An agent based approach to simulate production, degradation, repair, replacement and preventive maintenance of manufacturing systems
No full textThe capacity to be able to reconfigure the production systems is considered fundamental for the today manufacturing factories, due to the increasing request of a high performance of customer service level (lead time and price). For this reason, the simulation of the productivity of a specific configuration of a production line becomes a great assistance to the decision making process. This paper presents the potential of a multi-agent model used to simulate the failure behavior of a complex line production. This approach offers a decentralized alternative to design decision-making system based on the simulation of distributed entities. In particular, the presented model is able to independently manage the variations of the production rates and the failure prone, caused by the degradation of the machines, repair actions, and replacements. In addition, random failures, and preventive maintenance of a manufacturing system of a single product were considered. The blackboard system and the contract net protocol have inspired the manner to coordinate the productivity of the different machines in the production line, in order to simulate the highest feasible and most balanced productivity in different states of the line
A timed Petri net based approach for the design of industrial processes
No full textPurpose
The effective design of the industrial processes represents a key asset to compete and to create a sustainable value for each company. Such a complex issue needs to integrate technological, economical, environmental and safety constraints and opportunities to be mixed together through a win-win strategy. The development of useful, easy-use and flexible approaches to analytically support both the researchers and the practitioners in the process design, development and simulation is expected and strongly encouraged.
This paper focuses on the design and simulation of an industrial process adopting the timed Petri net approach. Considering a product flowing the manufacturing/assembly area and visiting a set of resources according to its working cycle, a timed Petri net design strategy is presented together with the static and dynamic analyses useful to predict the process key performances. The resource peculiarities, e.g. availability and conflicts, are, further, considered. A realistic case study is, finally, presented, to exemplify the proposed approach.
Design/methodology/approach
Starting from an overview of the timed Petri nets and their basic structure, the paper investigates an approach for their effective adoption in the industrial process design and simulation. An industrial and operative perspective is adopted and a case study is proposed to highlight the applicability of such a tool in a common operative context. The manufacture of a single product requiring dedicated resources and auxiliary devices is considered.
The proposed approach starts from the production process analysis to identify both the production features and the required resource characteristics. The timed Petri net design is, then, discussed adopting the most suitable approach, i.e. physical vs. functional. Given the net, its static and dynamic analysis and simulation is faced to obtain useful indices about the production process performances, e.g. the throughput, the required resources, the resource availability, the waiting times, etc. Such analysis outcomes represent useful guidelines to drive possible design or re-design actions.
Originality/Value
The Petri nets and, particularly, the timed Petri nets represent a well known mathematical modeling language for the description of the distributed systems. Their potential and opportunities to support the process design and simulation is discussed by the literature, together with a wide set of customization opportunities. From this perspective, several approaches are proposed. On the contrary, minor attention is paid to highlight the operative applicability of such a tool and, secondarily, to the development of effective static and dynamic drivers of analysis. Frequently, the Petri nets are studied on their own without a deep focus to the contexts in which they are applied. A lack of applicability of the obtained outcomes should occur.
This paper aim is to overcome such a weakness focusing on the applicability of the timed Petri nets to common operative contexts. Both the approach input and output are oriented to drive the process design. Furthermore, the proposed case study is realistic and its aim is to highlight the applicability and easy-use of the timed Petri nets for the industrial process analysis
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
EFFECTIVENESS OF DYNAMIC SIMULATIONSUPPORTING AND OPTIMIZING DESIGN AND MANAGEMENTOF WAREHOUSE FACILITIES
No full textThis paper presents some industrial applications of dynamic simulation techniques in order to show their effectiveness in supporting management decisions and to solve strategic and operative logistic problems.
Several significant real cases belonging to different business sectors, but always concerning the optimization of material handling system and manufacturing and distribution warehouse facilities’ design and management, are described. In the first one Visual Interactive Simulation (VIS) is used in order to design a physical temporary and distributive buffer warehouse; next an example of Montecarlo Simulation (MS) to support management and design of Automatic Storage & Retrievial System (AS/RS) is described. In conclusions two applications of VIS’s use to choose materials storage in different warehouse systems are presented and the impact of class based storage policy is emphasized.
Aim of this study is to show simulation approach’s effectiveness in order to optimize the Supply Chain (SC) according to the absolutely necessary need of integrating all business processes across intra and inter organizational boundaries and according to a competitive context where Customer wants more differentiated products in lower volumes and within shorter delivery times. The dynamic modeling approach based on simulation istruments passes through a hierarchical route of investigation which is made of some suboptimizations and involves simultaneously different entities of the integrated logistic channel. These relationships and influences are traditionally neglected in an ineffective modeling of a functional system. The efficiency and efficacy of simulation tools rise above static approaches, which are ineffective to consider all variables and constraints involved in real istances whose computational complexity is very hard.
After a qualitative description, the dynamic modeling of each industrial problem is illustrated thus justifying more significant and critical choices; hereafter all the results from the optimized process, which is based on simulative runs, are described
The influence of the picking times of the components in time and space assembly line balancing problems: An approach with evolutionary algorithms
No full textThe balancing of assembly lines is one of the most studied industrial problems, both in academic and practical fields. The workable application of the solutions passes through a reliable simplification of the real-world assembly line systems. Time and space assembly line balancing problems consider a realistic versions of the assembly lines, involving the optimization of the entire line cycle time, the number of stations to install, and the area of these stations. Components, necessary to complete the assembly tasks, have different picking times depending on the area where they are allocated. The implementation in the real world of a line balanced disregarding the distribution of the tasks which use unwieldy components can result unfeasible. The aim of this paper is to present a method which balances the line in terms of time and space, hence optimizes the allocation of the components using an evolutionary approach. In particular, a method which combines the bin packing problem with a genetic algorithm and a genetic programming is presented. The proposed method can be able to find different solutions to the line balancing problem and then evolve they in order to optimize the allocation of the components in certain areas in the workstation
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