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Sergio Amedeo GALLO

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Dipartimento Educazione e Scienze Umane
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Pubblicazioni

2014 - A Mono parameter analysis on a simulation model to support GALB heuristic optimization algorithms based on resource balancing [Relazione in Atti di Convegno]
Gallo, Sergio Amedeo; Davoli, Giovanni; Govoni, Andrea; Longo, Francesco; Melloni, Riccardo; Murino, Teresa
abstract

This paper is based on previous work that presented an approach and the related model to solve a GALB problem, and to analyse a multi model manual assembly line, based on heuristic algorithm to optimize the scheduling of tasks to the available stations, respecting a set of restrictions, as task/station obligation, and aiming to optimize a multi objective function based on time and line balancing costs elements. The assembly line we considered, process a very large variety of items, that differ for size, features, optional, under the increasing market competition. In that previous work, quite all strategies about resource scheduling opportunities have been considered. In the present step, we consider the last system we worked on, with a doubled number of stations, to test the reaction to the values changes of some configuration parameter as Due Date, Tardiness Cost, Tardiness Penal, Man work Direct Labour Cost, or Station Saturation.

2014 - Digital human models (DHM) to simulate meat processing to prevent work-related musculoskeletal disorders (WR-MSDs) [Relazione in Atti di Convegno]
Gallo, Sergio Amedeo; Melloni, Riccardo; Mosconi, Simone; Longo, Francesco
abstract

Work-Related Musculoskeletal Disorders (WRMSDs) are the leading cause of Occupational Disease in working populations of the advanced industrialized countries. The professional pathology of the upper limbs, from the 80's until today, is continuously increased to represent more than 50% of all occupational diseases. In literature many tools are available to perform the ergonomic assessment of the workplace. These tools and methods are classified based on the type of analysis that are able to perform and on the results that can provide. Beside the traditional methods of assessment, based on tabular theoretical methods, that commonly adopt paper check lists that refer to the main methods of analysis (NIOSH, OCRA, Snook & Ciriello, etc.), are available computer tools performing the same analysis, or, much more appropriate when it needs to make a more accurate biomechanical analysis. These methods provide numerical value indicating the level of risk to which workers are exposed.

2013 - Safety storage assignment in as/rs [Relazione in Atti di Convegno]
Davoli, Giovanni; Govoni, Andrea; Gallo, Sergio Amedeo; Bortoli, Erika; Melloni, Riccardo
abstract

Picking time reduction has been the traditional perspective for warehouse optimization. When structural safety is considered, optimization of warehouse operations should be read even in terms of load mass distribution. In many practical cases the static safety of the system is related to mass distribution and barycenter highness, for example when a vehicle hits the structure or even in the extreme case of an earthquake. To investigate the problem a simulation model is developed with AutoMod™ software. The model developed simulates a generalized AS/RS warehouse where the single physical location is managed. To evaluated the performances of the AS/RS a simulation experiment is completed. The aim of the experiment is to investigate the impact of different storage policies on intrinsic structural safety and performances in term of picking time and comparing the results with the variety caused by different factors such as: shuttle speed and warehouse filling rate. © 2013 DIME UNIVERSITÀ DI GENOVA.

2013 - Simulation for safety engineering: A comparison between experimental data and fire models [Relazione in Atti di Convegno]
Govoni, Andrea; Davoli, Giovanni; Gallo, Sergio Amedeo; Melloni, Riccardo
abstract

A comparison analysis has been conducted between experimental data of a concrete structure and three different models developed with CFAST, by NIST. This work concentrates on the possibility of modeling simplified fire objects. Full-scale experiments are simulated by two-layers zone models. Through a reverse approach on heat release rate estimation, a comparison between different models is reported analyzing time to flash over, maximum temperature, shape of the time-temperature curve. The possible use of these models as an engineering design tool is carried out. Results show that different ventilations lead to an uncertain time-temperature response. The benefits that should come from decomposition of fire load into many fire objects is counterbalanced by reduced accuracy due to increased model complexity and interactions between fire plumes. © 2013 DIME UNIVERSITÀ DI GENOVA.

2013 - Simulation model to analyze transport, handling, temporary storage and sorting issues: A valuable way to support layout, system definition and configuration and scheduling decision [Relazione in Atti di Convegno]
Gallo, Sergio Amedeo; Melloni, Riccardo; Murino, Teresa
abstract

The following paper describes the use of simulation models to analyze a common production scenario in manufacturing plants: many assembly lines producing specific families of items in a large variety of versions; following handling and transport system, evaluated to be effective, costless, with an adequate capacity to be not the bottleneck of the whole system, and integrated with a storage/sorting system to decoupling the assembly phase and the following ones as completion/test and expedition phase, included recovery and reform of the expedition lot. To analyze a system like this, a simulation model has been developed with a flexible AGVs transport system, a Transit Point Warehouse acted by AS/RS, used also as sorting media. The size of the warehouse incoming bay, number of warehouse sub allocation zones or aisles, the capacity of all queues, all control logics for AGV's have been evaluated in a pre-modeling phase, and then evaluated by the model. © 2013 DIME UNIVERSITÀ DI GENOVA.

2013 - Simulation models to support galb heuristic optimization algorithms based on resource balancing based on multi objective performance index [Relazione in Atti di Convegno]
Gallo, Sergio Amedeo; Davoli, Giovanni; Govoni, Andrea; Melloni, Riccardo
abstract

The following paper face with an approach to analyse a multi model manual assembly line, and the following heuristic algorithm to optimize the scheduling of tasks to the available stations, respecting of a set of restrictions, as task/station obligation, and aiming to optimize a multi objective function, based on time, balancing utilization rates, and line balancing costs elements. This problem can be considered as belonging to the wide area of GALB Problems. Some strategy about resource scheduling opportunities has been considered. The original referable configuration of the considered system is an assembly line with six stations, and with six operators. In the present step, the solution we experimented, shows a redundant (doubled) number of stations, to be a more flexible solution compared to previous solutions, with a layout too much specific and referred to the particular tasks and constrains profile, based on real data. © 2013 DIME UNIVERSITÀ DI GENOVA.

2010 - A stochastic simulation approach for production scheduling and investment planning in the tile industry [Articolo su rivista]
Davoli, Giovanni; Gallo, Sergio Amedeo; M. W., Collins; Melloni, Riccardo
abstract

The present paper aims to develop a simulation tool for tile manufacturing companies. The paper shows how simulationapproach can be useful to support management decisions related to production scheduling and investment planning. Particularlythe aim is to demonstrate the importance of an information system in tile firms. The Factory Data Model (FDM) parameter isused to describe the activities in ceramic tile industries operating in different European countries. A process- based analysis oftile manufacturers is undertaken and individual company performance is quantified by Key Performance Indicators (KPI). Theoverall model is composed of different processes, which are coded into Scilab environment and matched together to arrange astochastic simulator. The simulations results are used to show how management decisions can significantly effect the KPIs. Thesimulations highlight the effects on KPIs of three specific parameters: the length of scheduling period, the quantity of stockneeded and the reliability of the information system supporting orders. The results clearly show that the effect of allowing thepresence of unattended orders within the outstanding orders list always has a remarkable negative influence on KPIs. Resultsalso suggest that the presence of sub-groups of homogeneous tiles, based on colour variation, is one of the most importantfactors affecting a tile manufacturer’s performance. The results of the simulations have two different practical implications.Firstly, they demonstrate the importance of information systems in tile companies, suggest to evaluate investment ininformation technology and indicate the value of promoting an information culture in the entire work forces. Secondly, theyshow the potential of simulation tools development to support decision making in a BPR (Business Processes Re-engineering)scenario.

2010 - Development of a simulation model to increase in-line buffer performances [Relazione in Atti di Convegno]
Davoli, Giovanni; A., Govoni; Gallo, Sergio Amedeo; Melloni, Riccardo
abstract

The present paper aims to analyze an in-line buffer, composed of a belt conveyor system, by the use of discrete event simulation technique. The paper shows a case study relative to an engine production factory in the automotive field. The conveyor system is a dynamic buffer between engine production lines and testing stations. The aim of the analysis is to investigate the effects of different policies on testing stations balancing and lots management. In order to evaluate system performances different key performance indicators (KPIs) are considered. The system behavior is investigated under different conditions.

2010 - Lean Production in the ceramic industry: growth opportunities [Articolo su rivista]
Davoli, Giovanni; Gallo, Sergio Amedeo; A., Govoni; Melloni, Riccardo
abstract

I profondi cambiamenti imposti dalla globalizzazione a cui si sommano, oggi, gli effetti della crisi economico-finanziaria impongo alle aziende manifatturiere una ristrutturazione sia dei modelli organizzativi sia dei processi produttivi alla ricerca di una ritrovata competitività.Anche il settore ceramico viene sollecitato al cambiamento da una duplice e, per certi versi, contrastante esigenza. Da un lato la frammentazione del mercato impone lo sviluppo di un numero crescente di prodotti con cicli di vita che di anno in anno diventano più brevi. Dall’altra la presenza di una agguerrita concorrenza e le crescenti difficoltà nel reperimento di risorse impongono una modernizzazione dei processi produttivi tesa al contenimento dei costi tramite l’adozione di sistemi di produzione snella. La situazione odierna nel settore ceramico, per quanto riguarda la Lean Production (LP), vede ancora una scarsa diffusione delle pratiche tipiche della produzione snella. Il termine produzione snella (dall'inglese lean manufacturing o lean production) identifica una filosofia industriale che mira a minimizzare gli sprechi fino ad annullarli. Il processo produttivo, quindi, viene trattato in modo globale al fine di ridurre al massimo la complessità della produzione puntando sulla sua flessibilità e coinvolgendo fin dall'inizio tutte le funzioni aziendali.

2010 - VirtES (Virtual enterprise Simulator): a proposed methodology for enterprise simulation modeling [Relazione in Atti di Convegno]
Davoli, Giovanni; Gallo, Sergio Amedeo; Melloni, Riccardo
abstract

In this paper a methodology to develop simulation models is presented. The methodology is based on amulti-level simulation model which allows flexibility and process analysis. The present work starts fromapplied researches in different SME enterprises. Enterprise management often needs easy and fastdeveloped tools to increase production capacity and flexibility. In many cases performances increase ispossible only adopting a BPR (business processes reengineering) approach. Nevertheless the resistanceto a BPR approach is underlined in recent bibliography. The proposed approach consists of a three stagesmethodology, named VirtES (Virtual Enterprise Simulator). VirtES methodology was first applied toceramic tiles enterprises. The results achieved encourage the adoption to other industrial field.

2009 - A modular modelling approach to stochastic simulation of production – logistic systems [Relazione in Atti di Convegno]
Davoli, Giovanni; Gallo, Sergio Amedeo; A., Govoni; Melloni, Riccardo
abstract

The economic scenario today is highly competitive in terms of costs and number of competitors, so it isnecessary to adopt strategies that allow the constant improvement of manufacturing processes withinthe spending constrains. Simulation models are useful to support and drive company management inimproving the performances of production and logistic systems. The costs of simulation modeldevelopment could be reduced by the reuse of some of its parts. This work presents a case studyconcerning stochastic modeling of a small manufacture operating into the wood products field. Amodular simulation model composed of reusable sub-models has been developed using AutoMod™software package. The aim of the modular architecture is to allow the use of sub-models in differentproduction systems with little changes, decreasing the costs of development in order to became moreaffordable in a SME (small medium enterprise) contest.

2009 - Analysing the ceramic sector using processes and simulation models [Articolo su rivista]
Davoli, Giovanni; Gallo, Sergio Amedeo; Melloni, Riccardo
abstract

Industrial simulation involves making a virtual representationof a complex entity such as a ceramic company.Without needing to interact physically with the plant, thistechnique allows technical and economic performanceindicators to be evaluated, plant engineering andorganisational alternatives to be tried out and the mostsuitable solutions found for reducing investment andoperating costs and limiting industrial risks. These analyses areperformed by means of dedicated software platforms thatcreate a model of the company and its processes.

2008 - ANALYSIS OF INDUSTRIAL PROCESSES BASED ON INTEGRATION OF DIFFERENT SIMULATION TOOLS [Relazione in Atti di Convegno]
Davoli, Giovanni; Gallo, Sergio Amedeo; Melloni, Riccardo
abstract

The present paper provides an example of software tools integration in order to perform simulations incomplex industry models, such as a ceramic tile manufacture. The first part of the paper presents thefeatures of the two simulation tools adopted: AutoMod™ and VirtES. AutoMod™ is a commercial suiteof simulation tools witch provides an environment easy to develop highly accurate models for analysis.VirtES simulation tool was developed by the Industrial Plants Research Group of the Department ofIndustrial and Civil Engineering (DIMeC) of the University of Modena and Reggion Emilia. Modelsdeveloped in VirtES are useful to investigate macro Key Performances Indicators (KPI), such aseconomic indicators. The integrated used of VirtES and AutoMod™ allows to perform accuratesimulation at line production level developed by AutoMod™ in multiple virtual scenarios created byVirtES.

2008 - An improved step on evaluation of using a generic simulation package for processes to support SPR techniques as PERT and CPM [Relazione in Atti di Convegno]
Gallo, Sergio Amedeo; Melloni, Riccardo; Davoli, Giovanni
abstract

This paper represents an attempt to evaluate how a software tool to model and simulate process can support typical activities that any Project Manager commonly perform, and to enforce his work. In detail, It will be represented the whole work of programming activities, resources scheduling (man work especially), and their definition in team; moreover, we will see costs definition and planning, and the related control activity, and finally, periodical activities of progress control, and the following corrective actions. Structure, logics, any parameter and terminology in the model have been inspired to Network Programming Systems (NPS) like PERT, CPM, Man Scheduling, RAMPS, etc., of whom has been kept attitudes, conditioned just by specific most relevant needs in our contest and, stimulated, by opportunities offered by specific software simulating tool adoption. The case of project and process we referred to, is the activities flow deployed to reply to a commercial proposal and related price estimation for some equipment for tiles production in the ceramic field, and, under hypothesis of acceptance, the necessary following work flow to design, to produce and to supply and test at the customer plant. We adopted this hypothesis based on the big experience with this kind of equipment and of plants in this field, that made easier focus on the idea and on example we built, and to validate the hypothesis; on other hand, because in the case and contest we proposed, it should be more justified the burden to represent in a simulating model the entire flow of activities related to the project, in terms of time, cost, and effort, and should be easier replicate some part of the model structure, logics, and others, because of analogies that distinct project should present. Under these considerations, it’s possible obtain some structural repeatability, also if in light and apparent opposition with characteristics of uniqueness that each project has, under the most commons definitions about PM in literature. The use of a simulating “general purpose” SW should be achievable also to SME’s present in a so large amount in the Italian contest. Software tool is Arena of Rockwell.

2007 - Valutazione della scelta di una soluzione alternativa di sistema per il trasporto motori con tecniche simulative: il caso Lombardini Motori [Relazione in Atti di Convegno]
Gallo, Sergio Amedeo; Melloni, Riccardo
abstract

Il seguente studio si inquadra nella attività di collaborazione con l’azienda Lombardini Motori di Reggio Emilia, infatti,era già era stato analizzato in precedenza il sistema di trasporto dei motori tra i vari reparti (limitatamente allaporzione di processo che va dall’assemblaggio fino al magazzino spedizioni), i cui risultati sono stati presentati inuna precedente memoria. In questo lavoro si è cercata una soluzione alternativa al sistema preesistente perassicurare un aumento dell’efficienza, ed in particolare, un maggior livello di controllo informativo del trasferimento,una maggiore capacità di seguire ed adattarsi all’evoluzione del contesto produttivo che tende all’aumento del livellotecnologico, della flessibilità, della variabilità del mix e dei volumi produttivi. L’attuale sistema di movimentazione èun nastro trasportatore ad anello chiuso, piuttosto obsoleto, che costeggia e collega i vari reparti in cui vengonoeseguite le progressive lavorazioni. Le limitazioni riscontrabili nell’uso dell’attuale del nastro trasportatore sonorisultate 1) limitazioni relative al controllo dello smistamento dei vari tipi di motore ai vari gruppi freno, distinti pertipologia di collaudo effettuabile; 2) criticità relative alla rintracciabilità e alla tracciabilità dei motori, ed alla rottura deilotti sequenziali ed omogenei di motori; 3) la incapacità di supportare variazioni di allocazione dei banchi prova inrisposta alle variazioni di mix; 4) l’elevato impegno di lavoro ausiliario umano per complementare il sistema ditrasporto. Il sistema che è risultato più convincente per una valutazione in simulazione è risultato essere un LaserGuided Vehicle System (LGVS). La modellazione è stata effettuata utilizzando il pacchetto Arena 8.0 della RockwellSoftware.

2007 - Valutazione dell’uso di un Applicativo di Simulazione di Processi Generico a Supporto delle Tecniche dei SPR quali PERT e CPM [Relazione in Atti di Convegno]
Gallo, Sergio Amedeo; Melloni, Riccardo
abstract

Questo lavoro rappresenta un tentativo di valutare l’uso di uno strumento SW per la modellazione e lasimulazione a supporto delle attività tipiche che un Project Manager esegue per la conduzione di unprogetto per potenziarne le capacità. In particolare verrà rappresentata e trattata la attività diprogrammazione delle attività, schedulazione delle risorse umane e definizione in squadre, lapianificazione dei costi e loro controllo, nonché le attività periodiche di controllo avanzamento ed i relativiinterventi correttivi. La struttura, lo strumento, le logiche, le determinazioni e terminologia usata nellamodellazione saranno ispirate ai metodi degli SPR: PERT, CPM, Man Scheduling, ecc., di cui si è cercatodi acquisire le prerogative, ispirati dalle necessità del contesto della nostra ipotesi, e dalle opportunitàofferte dall’uso dell’applicativo di simulazione. L’ipotesi di processo o progetto cui si è fatto riferimento èquella di predisposizione di un preventivo e relativa fornitura di equipaggiamenti ed impianti di produzioneper il settore ceramico, a partire dal recepimento ed elaborazione nel sistema aziendale di una richiestafornitura e delle relative specifiche, scelta dettata, da un lato per una certa conoscenza diretta dellecaratteristiche di tali sistemi produttivi e delle aziende di impiantistica nel settore, e quindi, una maggiorepossibilità di validazione dell’esempio, per altri aspetti, per la considerazione che l’onere dirappresentazione in un modello di simulazione del flusso delle attività correlate a questo contesto, intermini di tempo, costo ed impegno, avesse opportunità di essere ammortizzato in relazione alle analogieche presentano le diverse richieste di fornitura, configurandosi un aspetto di parziale ripetibilità strutturale,anche se in apparente contrasto con le caratteristiche di unicità che ogni progetto presenta, secondo ladefinizione propria delle trattazioni sul Project Management (PM). L’utilizzo dell’applicativo di simulazionegeneral purpose è abbordabile anche per le piccole aziende di fornitura impiantistica, particolarmentenumerose nel contesto italiano. Il pacchetto SW utilizzato è Arena della Rockwell.