A Method for reducing throughput-time in industrial electronics

Lyhyet toimitusajat tuovat yrityksille kilpailuetua nopeasti muuttuvassa teollisuusympäristössä. Tämän diplomityön ensisijaisena tavoitteena on löytää kirjallisuuden avulla yrityksen käyttöön soveltuva menetelmä, joka soveltuu systemaattiseen läpimenoaikojen lyhentämiseen. Tärkeää on myös varmistaa valitun menetelmän soveltuvuus kohdeyrityksen ympäristöön. Työn toisena tavoitteena on ymmärtää, että minkälaisella panostuksella yhden päivän läpimenoaika voidaan saavuttaa. Kirjallisuustutkimuksen avulla on valittu tarkoitukseen sopiva toimintamalli. Menetelmä on testattu yhdellä tuotantolinjalla ja saadut tulokset sekä palaute osoittavat, että se näyttäisi soveltuvan kohdeyrityksen käyttöön. Tuotantolinjalle on tehty toimintasuunnitelma yhden päivän toimitusajan saavuttamiseksi vuoden 2013 aikana. Haasteen laajuutta koko kohdeyrityksessä on tutkittu erillisessä ideointisessiossa. Session tulosten perusteella on tehty prioriteettilista, joka antaa käsityksen toimitusajan merkittävän lyhentämisen vaatimuksista. Yleisesti ottaen kysynnän vaihtelun hallinta on suurin haaste, mutta useita ratkaisuvaihtoehtoja tämän hallitsemiseksi on tunnistettu.

Production of pizza dough with reduced fermentation time

The aim of this study was to reduce the fermentation time of pizza dough by evaluating the development of the dough during fermentation using a Chopin® rheofermentometer and verifying the influence of time and temperature using a 2² factorial design. The focus was to produce characteristic soft pizza dough with bubbles and crispy edges and soft in the center. These attributes were verified by the Quantitative Descriptive Analysis (QDA). The dough was prepared with the usual ingredients, fermented at a temperature range from 27 to 33 ºC for 30 to 42 minutes, enlarged, added with tomato sauce, baked, and frozen. The influence of the variables time and temperature on the release of carbon dioxide (H'm) was confirmed with positive and significant effect, using a rheofermentometer, which was not observed for the development or maximum height of the dough (Hm). The same fermentation conditions of the experimental design were used for the production of the pizza dough in the industrial process; it was submitted to Quantitative Descriptive Analysis (QDA), in which the samples were described by nine attributes. The results showed that some samples had the desired characteristics of pizza dough, demonstrated by the principal component analysis (PCA), indicating a 30 % fermentation time reduction when compared to the conventional process.

Production lot sizing and scheduling with non-triangular sequence-dependent setup times

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Melhoria do processo de reparo por meio da redução de Lead Time em uma empresa de som automotivo

The constant search for improvement and survival of the companies makes essential the utilization of cost reduction strategies and resources optimization. This study had as its objective the utilization of Lean Manufacturing tools for the repair process lead time reduction, in a car audio manufacturer. Performing an action research, the major problems were studied, such as the potential causes and the possible improvement activities, using the DMAIC methodology. An action plan was developed for all involved processes and, as a result, the objective was reached by making a direct impact on the customers’ satisfaction and adding a competitive differential for the company

Redução de tempo de setup de uma máquina de encartuchamento pela técnica SMED

Currently the market requires companies to adapt for they can have the lowest possible cost in their manufacturing, be it a good or service, thus obtaining a greater profit. For this profit the Toyota Production System applies lean manufacturing practices actions with reduced spending, smaller lots and stocks, generated by market demand. The technique allows SMED with few actions, changes and investments that time does not exceed one digit on your total time. This case study shows that only with standardization and use of inexpensive improvements, could reduce setup time on a machine for 70 minutes to time of approximately 48 minutes with little investment, demonstrating the viability of the tool presented

Redução de tempos de setup: aplicação de troca rápida de ferramentas em indústria de bebidas

The current competitive market requires companies to adapt so that they can meet the needs of customers in an agile manner and aimed at the lowest possible cost in their manufacture, be it a product or service. The Toyota Production System is aimed at higher profits through lean manufacturing practices with reduced spending, smaller lots and inventories, generated by market demand. The variety of products makes the setup of the equipment a critical point and it should be reduced as much as possible so it does not affect productivity. The rapid exchange of tools allows with few actions and a modification that time does not exceed one digit on your total time. In this study, a case study showed that only with standardization and use of cheap improvements made it possible to reduce setup time in bottle labeling machine by 98 minutes for a final time of approximately 10 minutes with little investment, demonstrating the feasibility the displayed and a monthly gain tool in bottles at approximately 120,000, generating a performance gain and budget of approximately R$ 94,000.00 per month

Redução de tempos de setup: aplicação de troca rápida de ferramentas em indústria de bebidas

The current competitive market requires companies to adapt so that they can meet the needs of customers in an agile manner and aimed at the lowest possible cost in their manufacture, be it a product or service. The Toyota Production System is aimed at higher profits through lean manufacturing practices with reduced spending, smaller lots and inventories, generated by market demand. The variety of products makes the setup of the equipment a critical point and it should be reduced as much as possible so it does not affect productivity. The rapid exchange of tools allows with few actions and a modification that time does not exceed one digit on your total time. In this study, a case study showed that only with standardization and use of cheap improvements made it possible to reduce setup time in bottle labeling machine by 98 minutes for a final time of approximately 10 minutes with little investment, demonstrating the feasibility the displayed and a monthly gain tool in bottles at approximately 120,000, generating a performance gain and budget of approximately R$ 94,000.00 per month

An efficient ‘a priori’ model reduction for boundary element models

The Boundary Element Method (BEM) is a discretisation technique for solving partial differential equations, which offers, for certain problems, important advantages over domain techniques. Despite the high CPU time reduction that can be achieved, some 3D problems remain today untreatable because the extremely large number of degrees of freedom—dof—involved in the boundary description. Model reduction seems to be an appealing choice for both, accurate and efficient numerical simulations. However, in the BEM the reduction in the number of degrees of freedom does not imply a significant reduction in the CPU time, because in this technique the more important part of the computing time is spent in the construction of the discrete system of equations. In this way, a reduction also in the number of weighting functions, seems to be a key point to render efficient boundary element simulations.

Proposta de implementação de uma metodologia SMED numa metalomecânica

O presente trabalho é o resultado de um projecto experimental que teve como principal objetivo a redução dos tempos de setup, através da implementação da metodologia Single Minute Exchange of Die (SMED) em equipamentos de eletroerosão (EDM) por fio e penetração. Para garantir o sucesso da implementação, após uma revisão bibliográfica centrada no tema SMED, estabelece-se uma metodologia, numa lógica de melhoria contínua análoga a um ciclo PDCA. A metodologia estabelecida envolve as seguintes fases: caracterização da situação inicial, observação, recolha de dados, análise dos dados e implementação SMED. A caracterização da situação inicial visa qualificar a situação encontrada e identificar a zona de atuação - equipamentos em estudo. A observação do processo produtivo é suportada pela ferramenta fluxograma do processo, por sua vez, a recolha de dados visa a avaliação inicial e nessa perspectiva recorre-se à abordagem OEE. Na fase de análise dos dados são introduzidas as ferramentas de análise VSM e diagrama de causa e efeito que auxiliam a identificação de um conjunto de acções de melhoria, a realizar previamente à fase de implementação SMED, culminando assim uma fase PRÉ-SMED. Reunidas as condições ideais iniciou-se a implementação efectiva da metodologia SMED obtendo-se reduções do tempo total de setup superiores a 60%. O presente estudo permite concluir que podem surgir diferenças significativas em diversas aplicações SMED, enfatizando a importância de uma fase PRÉ-SMED de modo a potenciar os resultados alcançados com uma implementação SMED.

A state-space modeling approach for active structural acoustic control

The demands for improvement in sound quality and reduction of noise generated by vehicles are constantly increasing, as well as the penalties for space and weight of the control solutions. A promising approach to cope with this challenge is the use of active structural-acoustic control. Usually, the low frequency noise is transmitted into the vehicle`s cabin through structural paths, which raises the necessity of dealing with vibro-acoustic models. This kind of models should allow the inclusion of sensors and actuators models, if accurate performance indexes are to be accessed. The challenge thus resides in deriving reasonable sized models that integrate structural, acoustic, electrical components and the controller algorithm. The advantages of adequate active control simulation strategies relies on the cost and time reduction in the development phase. Therefore, the aim of this paper is to present a methodology for simulating vibro-acoustic systems including this coupled model in a closed loop control simulation framework that also takes into account the interaction between the system and the control sensors/actuators. It is shown that neglecting the sensor/actuator dynamics can lead to inaccurate performance predictions.

A Functional Verification Methodology Based on Parameter Domains for Efficient Input Stimuli Generation and Coverage Modeling

Modern Integrated Circuit (IC) design is characterized by a strong trend of Intellectual Property (IP) core integration into complex system-on-chip (SOC) architectures. These cores require thorough verification of their functionality to avoid erroneous behavior in the final device. Formal verification methods are capable of detecting any design bug. However, due to state explosion, their use remains limited to small circuits. Alternatively, simulation-based verification can explore hardware descriptions of any size, although the corresponding stimulus generation, as well as functional coverage definition, must be carefully planned to guarantee its efficacy. In general, static input space optimization methodologies have shown better efficiency and results than, for instance, Coverage Directed Verification (CDV) techniques, although they act on different facets of the monitored system and are not exclusive. This work presents a constrained-random simulation-based functional verification methodology where, on the basis of the Parameter Domains (PD) formalism, irrelevant and invalid test case scenarios are removed from the input space. To this purpose, a tool to automatically generate PD-based stimuli sources was developed. Additionally, we have developed a second tool to generate functional coverage models that fit exactly to the PD-based input space. Both the input stimuli and coverage model enhancements, resulted in a notable testbench efficiency increase, if compared to testbenches with traditional stimulation and coverage scenarios: 22% simulation time reduction when generating stimuli with our PD-based stimuli sources (still with a conventional coverage model), and 56% simulation time reduction when combining our stimuli sources with their corresponding, automatically generated, coverage models.

Kinetics of solute leachate from imbibing Caesalpinia echinata Lam. (Brazilwood) seeds

The electrical conductivity of leachates from imbibing seeds has been used as a vigor test for several species. The adaptation of this methodology to different species requires knowledge on the leaching kinetics of electrolytes. For Brazilwood seeds, the classic method was not satisfactory and rapid tests are essential because they have low storage capacity at room temperature. Leaching kinetics during seed imbibition is a function of physiological quality, presence or absence of seed coat, imbibing temperature and the initial moisture content of seed. In this study, the electrolyte leaching rate of six different categories of seeds, from two regions, was evaluated in seeds with and without seed coat and incubated with different moisture contents and at different temperatures. The results showed that the electrolyte leaching rate in Brazilwood seeds is independent of the physiological quality, the presence or absence of seed coat and imbibition temperature, but these factors changed the total amount of electrolytes leached. The leaching rate increased in the first few minutes of imbibition, suggesting that the adjustment of the methodology must consider the reduction in imbibition time, reduction in temperature, use of a controlled and slower pre-imbibition, and replacement of the imbibition solution after the first few minutes.

Concepção e instalação de tabelas multifunções para recintos desportivos cobertos

Mestrado em Engenharia Electrotécnica – Sistemas Eléctricos de Energia

Melhoria do processo de fabrico de esterilizadores

Mestrado em Engenharia Mecânica. Gestão de Processos e Operações.

Comparative study about heating systems for pultrusion process

Different heating systems have been used in pultrusion, where the most widely used heaters are planar resistances. The primary objective of this study was to develop an improved heating system and compare its performance with that of a system with planar resistances. In this study, thermography was used to better understand the temperature profile along the die. Finite element analysis was performed to determine the amount of energy consumed by the heating systems. Improvements were made to the die to test the new heating system, and it was found that the new system reduced the setup time and energy consumption by approximately 57%.