Fabiano Leal

Conceptual modeling in simulation projects by mean adapted idef: an application in a brazilian tech company

Several process modeling techniques have been used in simulation projects. However, most of these techniques provide little specific support to the programming. The main cause of this is the fact that these techniques were not developed with the same logic used in simulation models. From this issue, this paper presents an industrial application of a new conceptual modeling technique, named IDEF-SIM (Integrated Definition Methods - Simulation) currently under development by the authors. This adapted IDEF uses logic elements present in techniques such as IDEF0 and IDEF3, but in a way that is similar to the process interpretation logic usually used in simulation projects. This way, it can be noticed an increase in the conceptual models utility, which might facilitate the simulation model programming, verification and validation and the scenarios creation. Additionally, the paper presents the benefits of using IDEF-SIM to create the conceptual model of a Brazilian tech company manufacturing cell.

Integration of computer simulation in design for manufacturing and assembly

As a reason for competitiveness, the process of product development evolves using, in some situations, improvement methods, e.g. design for manufacturing and assembly (DFMA). In the framework of the product development process, it is desirable that engineers and managers have a systemic view of the effects that changes in local processes will have on the overall performance of the entire production system. This vision of such effects can be achieved with computer simulation. This study aims at assessing how DFMA can be integrated with computer simulation and the benefits from the alternatives identified by such method during production and assembly. Using the electronic voting machine printer as object of study, options to improve design by means of DFMA principles are identified. Five models were developed to represent the current assembly process and two models following the implementation of the changes proposed by the DFMA. The sale price is confidential (exclusive product of the Brazilian government). The company provided data in assembly costs. The results show the production increase in assembly time (9.94%) and average daily sales (

Combined use of modeling techniques for the development of the conceptual model in simulation projects

415).

A practical guide for operational validation of discrete simulation models

The objective of this paper is to utilize the SIPOC, flow-chart and IDEF0 modeling techniques combined to elaborate the conceptual model of a simulation project. It is intended to identify the contribution of these techniques in the elaboration of the computational model. To illustrate such application, a practical case of a high-end technology enterprise is presented. The paper concludes that the proposed approach eases the elaboration of the computational model.

Gestão do Conhecimento na análise de falhas: mapeamento de falhas através de sistema de informação

As the number of simulation experiments increases, the necessity for validation and verification of these models demands special attention on the part of the simulation practitioners. By analyzing the current scientific literature, it is observed that the operational validation description presented in many papers does not agree on the importance designated to this process and about its applied techniques, subjective or objective. With the expectation of orienting professionals, researchers and students in simulation, this article aims to elaborate a practical guide through the compilation of statistical techniques in the operational validation of discrete simulation models. Finally, the guides applicability was evaluated by using two study objects, which represent two manufacturing cells, one from the automobile industry and the other from a Brazilian tech company. For each application, the guide identified distinct steps, due to the different aspects that characterize the analyzed distributions

Interactive learning of modeling and discrete-events simulation through Lego® parts

The managerial excellence is based on the company competence to produce, store and disseminate knowledge. Such an importance is even more justified by the use of knowledge to analyze failures in order to avoid undesirable consequences and guarantee the system reliability. In this context, this article presents a Knowledge Management application in an electric energy company. The main aim of this article is to present a method for mapping failures through an information system. This system provides failure trees, which storage photos, procedures, management descriptions of failures and, to avoid relapse, previous ways of solutions. In short, this work provides a practical application of the Knowledge Management approach to the failure analysis subject.

Economic evaluation of the increase in production capacity of a high technology products manufacturing cell using discrete event simulation

A discrete-events simulation course should develop in its students not only the abilities related to the programming language and statistical analysis, but also the ability to create an abstract of a real system into a model system. Thus, this paper has the objective to develop and evaluate an educational dynamic project for discrete event simulation courses, which are capable of developing the students ability to perform abstraction and representation of real systems in a conceptual and computational model. To meet this objective, Lego® was used in the educational dynamic. For the evaluation of the motivation presented by the students in the dynamic, the ARCS (Attention, Relevance, Confidence, Satisfaction) technique was used together with an Instructional Materials Motivational Survey (IMMS) questionnaire. An indicator was established to measure the students utilization and/or knowledge gained. The results demonstrate that the dynamic reached its objective, presenting a high utilization in the motivational criteria analyzed.

ANÁLISE DE FALHAS ATRAVÉS DA APLICAÇÃO DO FMEA E DA TEORIA GREY

This paper presents an application of the modeling and simulation methodology along with the Design of Experiments (DOE) to aid the decision makers to know the economic risk they are taking when there are many scenarios. Firstly, the production process was studied and documented by a SIPOC, an IDEF0 and a Flowchart. These techniques were combined to elaborate the simulation conceptual model. After that, the probability distributions were chosen and fed the computer model, built to emulate the real system. The simulation model was verified and statistically validated. Sixty four possible scenarios were tested, and in this case, the DOE may contribute to select the scenarios which are relevant to the economic analysis. The simulator used was Promodel® which provided the output to fed the cash flow of each scenario. Finally, the Net Present Value (NPV) and the economic risk of each scenario were calculated.

URBAN SOLID WASTE MANAGEMENT BY PROCESS MAPPING AND SIMULATION

Este artigo tem como objetivo analisar as causas de falhas potenciais atraves da avaliacao do RPN (risk priority number), apresentado na literatura na abordagem do FMEA (Failure Mode and Effect Analysis). O RPN sera determinado atraves da teoria Grey, contribuindo desta maneira para contornar alguns problemas apresentados na literatura a respeito do metodo tradicional de calculo do RPN. O artigo apresentara uma descricao passo a passo desta tecnica, aplicada ao processo de distribuicao de energia eletrica. Para isto, foram analisadas algumas falhas identificadas em uma distribuidora. Por fim, a analise considerou uma ponderacao diferente para os fatores do FMEA, evidenciando as possibilidades de analise desta tecnica.

Using Discrete-Event Simulation in Urban Solid Waste Selection

Adequate management of urban solid waste (USW) is beneficial to the environment, cities and people who depend on the income generated from collecting this waste material to survive. Due to the level of complexity of these processes involved in recyclable USW sorting, management tools which enable systemic studies become valuable assets by evaluating the effects changes may cause on the organization. This paper presents a modeling study, which used process mapping and discrete event simulation, in which a USW collection process was evaluated. The study was conducted in conjunction with the USW trash gatherers association of Itajuba, state of Minas Gerais, Brazil. The lack of standardized processes presented difficulties for developing the simulation model. To diminish this problem, three conceptual modelingtechniques were used (SIPOC, flowcharts and IDEF-SIM). Data were collected via observation, interviews and questionnaires. The validated conceptual model, obtained in this study, will be able to be used to better understand the process. Finally, the model was used to evaluate process improvement scenarios.