Assembly Factory Research Articles

El género, la fábrica y la vida urbana en la frontera / Gender, Workplace and Urban Living in the Border

Este artículo tiene como objetivo contribuir a la reflexión acerca de los cambios socioculturales en la vida de las mujeres trabajadoras de la maquiladora en la época contemporánea. Para ello se elaboró un ejercicio interpretativo de un conjunto de narraciones, entre las que se incluyeron a modo de contraste los casos de algunos hombres. En particular se analizan el contexto y la experiencia de vida de las personas que acceden a estos empleos, su orientación laboral, la negociación identitaria que se presenta en las fábricas y la construcción del sentido de pertenencia al trabajo. Asimismo se examina el impacto de este modelo de industrialización en la configuración de los modos de vida tradicionales y modernos en la ciudad de Tijuana. AbstractThe aim of this article is to analyze the actual social and cultural change in women’s lives as workers of the border assembly factories. An interpretative exercise has been done for these purpose using a set of women and men narratives. In particular, we analyze the context and life experience of working women and men, its labor orientation, the gender identity negotiation in the factories and the construction of the sense of belonging to work. Also, the impact of this model of industrialization on the configuration of traditional and modern ways of life in the city of Tijuana is discussed.

Prevalence and associated ergonomic factors of radial styloid tenosynovitis among electronic assembly workers in Thailand

Objectivesto determine the magnitude, distribution and associated ergonomic factors of radial styloid tenosynovitis among electronic assembly workers in Thailand.Methodsthe design was a cross-sectional study. 591 of 853 workers in an...

Sequencing Mixed Model Assembly Lines Based on Genetic Algorithm Optimization

Firstly, genetic algorithm optimization method was put forward to solve optimization problems of sequencing in actual mixed model passenger car factory assembly line. Then genetic algorithm optimization methods and procedures of mixed model total assembly line production sequencing were studied. Finally, according to the characteristics of the mixed production line, the least total waiting time of vehicle was set to complete assembly as a sequencing optimization objective, the AutoMod simulation software was used to balance the allocation of resources and optimize the sequence by way of genetic algorithm, and the optimal sequencing solution was obtained. After optimization and balance, the total waiting time of mixed model vehicles in complete assembly line was reduced by 69.5%, which improves production efficiency greatly. This also proves the effectiveness of genetic algorithm optimization.

English

The objective of this study is to determine the dominance effects of environmental factors such as illuminance, humidity and WBGT on operators’ productivity in the Malaysian automotive industry. A case study was carried out at an automotive components assembly factory. The environmental factors examined were the illuminance (lux), humidity and WBGT of the surrounding workstation area. Two sets of representative data including the illuminance, humidity and WBGT level and production rate were collected during the study. The production rate data were collected through observations and survey questionnaires while the illuminance level was measured using photometer model RS 180-7133, and the humidity and WBGT level were measured by using Quest Temp apparatus and humidity. The Taguchi method was utilized to find the sequence of dominant factors that contributed to the productivity of the operator at that specified production workstation. The study reveals that the dominant factor that contributed to the productivity was humidity, followed by illuminance and WBGT.

Application of Dynamic Programming in Resources Optimization Allocation of Factory Production Line

The dynamic programming has significant implications for solving multi-stage decision of resource allocation problems. By inducting phase, state of variables and decision, the factory assembly line resource allocation problems was taken as a multi-stage decision process. The stage of resource allocation was divided in reason, and the dynamic programming equation was built with “Top-Down” ways to reverse recursion according to the dynamic programming principle and methods. Adopting the MATLAB7.0 as development platform, it was convenient for calculating optimal decision sequence and maximum total profits. Dynamic programming method has obvious effect in equipment resource allocation output issues, and brings in the biggest economic benefits in limited investment.

An Systematic Modeling and Simulation Study on WIP Optimization in Semiconductor Assembly and Test Factory

The simulation, modeling and analysis of manufacturing systems for performance improvement have become increasingly important during the last few decades. This paper presents a practical solution to a manageable and well distributed work in process (WIP) control system with simulation experiment demonstrated by constructing the virtual production lines, addressing issues such as wafer kitting strategy, critical work in process level setting. The simulation WIP instances are coordinated and synchronized with production line influence factors and activities imported. Through the testing and actual practice, this simulation tool helps semiconductor assembly and test factory production managers effectively manage work-in-process (WIP) levels to compensate the impact of unexpected production variations and achieve better factory performance.

The Optimization of Environmental Factors at Manual Assembly Worstation by Using Taguchi Method

The objective of this study was to determine the dominance effects of environmental factors such as Illuminance, humidity and WBGT on the operators’ productivity at Malaysian automotive industry. A case study was carried out at an automotive components assembly factory. The environmental factors examined were the Illuminance (lux), humidity and WBGT of the surrounding workstation area. Two sets of representative data including the illuminance, humidity and WBGT level and production rate were collected during the study. The production rate data were collected through observations and survey questionnaires while the illuminance level was measured using photometer model RS 180-7133, the humidity and WBGT level were measured by using quest temp thermal environment monitor. Taguchi Method was utilized to find the sequence of dominant factors that contributed to the productivity of operator at that specified production workstation. The study reveals that the dominant factor contributed to the productivity was illuminance, followed by humidity and WBGT.

Optimization of Several Environmental Factors to Human Performance by Using Taguchi Method

The objective of this study is to determine the dominance effects of environmental factors such as Illuminance, humidity and Wet Bulb Globe Temperature (WBGT) on the operators' productivity at Malaysian electronic industry. A case study was carried out at an electronic components assembly factory. The environmental factors examined were the Illuminance (lux), humidity and WBGT of the surrounding workstation area. Two sets of representative data including the illuminance, humidity and WBGT level and production rate were collected during the study. The production rate data were collected through observations and survey questionnaires while the illuminance level was measured using photometer model RS 180-7133, the humidity and WBGT level were measured by using Quest Temp apparatus and humidity. Taguchi Method was utilized to find the sequence of dominant factors that contributed to the productivity of operator at that specified production workstation. The study reveals that the dominant factor contributed to the productivity was WBGT, followed by illuminance and humidity.

Optimization of a multi-Constant Work-in-Process semiconductor assembly and test factory based on performance evaluation

This paper considers a semiconductor assembly and test factory which is a three-segment-Constant Work-in-Process (CONWIP) system with overlapping machines. In the system, three types of carts circulate for meeting the physical requirements. The optimization problem in setting the suitable total Work-in-Process (WIP) level and the distribution in the three loops from the view of the trade-off between the throughput and the WIP level for the system is addressed. In the proposed model, the system is firstly modeled as a three-loop closed queue network and we propose an approximate method to evaluate the performance. The accuracy of the evaluation method was illustrated by numerical experiments, indicating that the method is fairly precise. Secondly, a Genetic Algorithm is designed to obtain near optimal results based on the performance evaluation. The semiconductor assembly and test system case as well as the application procedure were carried out in detail.

Devising an unconventional formal logic for bioinspired spacefaring automata

The field of robotics is increasingly moving from robots confined to factory floors and assembly lines and bound to perform the same tasks over and over in an uncertainty-free, well foreseeable environment, to robots designed for operating in highly dynamic and uncertainty domains, like those of interest in space exploration. According to an idea of a “new system of formal logic less rigid than past and present formal logic” advocated by von Neumann for building a powerful theory of automata, such system should be “closer to another discipline which has been little linked in the past with logic, i.e. thermodynamics, primarily in the form it was received by Boltzmann”. Following that idea, which is particularly interesting now with the emerging computational nano-sciences, it is stressed here that a full set of isomorphisms can be established between the fundamental logical principles and the information flows, Hamiltonian or dissipative, in phase space. This form of logic, dubbed here kinetic logic, takes standard formal logic out of the field of combinatorics and into the field of the Boltzmannian form of thermodynamics, i.e. kinetics.

Proving external validity of ergonomics and quality relationship through review of real-world case studies

Prior lab experiment and simulated environment ergonomics studies revealed the cause-and-effect relationship between ergonomics and quality with high internal validity. However, the external validity, i.e. the generalisability of this relationship to field settings (manufacturing plants) cannot be ascertained unless field experiment studies are conducted. Therefore, the current study aims to review five field experiment ergonomics studies to strengthen the external validity of this relationship. The studies reviewed include Axelsson (2000. Quality and ergonomics: Towards successful integration. Thesis (PhD). Linköpink University) in an assembly plant, Gonzalez et al. (2003. Ergonomic performance and quality relationship: an empirical evidence case. International Journal of Industrial Ergonomics, 31 (1), 33–40) in metal manufacturing, Yeow and Sen (2003. Quality, productivity, occupational health and safety and cost effectiveness of ergonomic improvements in the test workstations of an electronic factory. International Journal of Industrial Ergonomics, 32 (3), 147–163; 2006. Productivity and quality improvements, revenue increment, and cost reduction in the manual component insertion lines through the application of ergonomics. International Journal of Industrial Ergonomics, 36 (4), 367–377) in printed circuit assembly factories, and Erdinc and Vayvay (2008b. Ergonomics interventions improve quality in manufacturing: a case study. International Journal of Industrial and Systems Engineering, 3 (6), 727–745) in a textile factory. The manufacturing tasks, ergonomics and quality methodologies, ergonomics problems, ergonomics interventions, and quality improvement outcomes were examined. The study found that ergonomics problems, particularly awkward postures, cause human error which results in quality defects. All studies show significant reduction in defects and three studies show financial gains, i.e. savings on rejection costs. This research provides researchers and engineers an insight into why ergonomics problems can lead to poor quality and how to assess such problems and apply ergonomics interventions for higher quality performance in manufacturing.

Distributed supply chain in a global environment

A localised production system is no longer a competitive advantage in today's globalised economy. Instead, production systems are becoming decentralised increasingly due to several benefits. This decentralised production strategy influences firms to establish more and more coordination among various suppliers globally. A better communication infrastructure is required to control these huge supply networks effectively and efficiently. In this paper, we have demonstrated how different distributed supply chain networks can be managed appropriately by using software named ASDN. A hypothetical car engine assembly factory within Europe was considered for demonstration, where engine components were outsourced through different suppliers within Europe.

Kinesthetic Assistance for Improving Task Performance -The Case of Window Installation Assist-

Industrial robots have been widely used in factory automation. On the other hand, in the final assembly in automobile factories, many tasks are still completed by humans due to the difficulties and costs associated with automation. One example still requiring skilled human operators is the installation of the automobile window. The window installation assist robot we developed enables a single operator to install a window easily. The present study focuses on kinesthetic assistance including preliminary experiments and application to automobile window installation during car assembly demonstrating the effectiveness of our proposal.

Thermal Comfort Assessment and Optimization of Environmental Factors by Using Taguchi Method

Problem statement: The objective of this study was to determine the dominance effects of environmental factors such as Illuminance (lux), relative humidity (%) and WBGT (°C) on the operators’ productivity at Malaysian automotive industry. Approach: One automotive parts assembly factory had been chosen as a subject for the study. The subjects were workers at the assembly section of the factory. The environment examined was the Illuminance (lux), relative humidity (%) and WBGT (°C) of the surrounding workstation area. Two sets of representative data including the Illuminance, relative humidity (%) and WBGT (°C) level and production rate were collected during the study. All the data was measured using Babuc apparatus which is capable to measure simultaneously those mentioned environmental factors. The time series data of fluctuating level of environmental were plotted to identify the significant changes of factors. Then Taguchi Method was being utilized to find the sequence of dominance factors that contributed to the productivity of operator at the specified production workstation. From there, optimum level for the three factors will be determine for optimum productivity. Further multiple linear regressions were employed to obtain the equation model in order to represent the relationship of these environmental factors towards productivity. Results: the thermal comfort assessments of this station which was the scale PMV was 2 and PPD is 79% ware likely to be satisfied by the worker. Conclusion: The study revealed that the dominant factor contribute to the productivity at the body assembly production line is WBGT and Illuminance whereas the empirical finding was closely related to the perception study by survey questionnaire distribution.

The Design and Development of an Adaptable Modular Sustainable Commercial Building (Co2nserve) for Multiple Applications

Co2nserve is a commercially sponsored project aimed at developing a cost effective modular building that is able to meet sustainability, energy and carbon efficiency needs, and is adaptable to meet a wide range of occupancy applications. Building applications include light industrial production, warehousing, office accommodation, educational needs and health sector requirements. This paper describes the building development and design process. Maximum use is made of passive measures including natural ventilation, and natural cooling. Structural and envelope elements have been designed for factory assembly using sustainable and/or recyclable components. A key part of the design process was to establish a multi-disciplinary design group at the start of the project. This group met on a regular basis to evolve the design. The design has achieved a Class A Energy Performance Certificate under the requirements of the European Energy Performance of Buildings Directive. The building is ready for construction; a development site and occupier for the first building is currently being identified.

Thermal Comfort Assessment: A Case Study at Malaysian Automotive Industry

Problem statement: Thermal comfort has a great influence on the productivity and satisfaction of indoor building occupants. The exposure to excessive heat during work may cause discomfort and contributed to low productivity among workers. Malaysia known with its hot and humid weather where in most of the survey study published indicated that workers in Malaysia automotive industries had exposed to excessive temperature while working. The study investigated the thermal comfort level experienced by workers at Malaysian automotive industry. Approach: The study had been conducted at one automotive parts assembly factory in Malaysia. The human subjects for the study constitute operators at tire receiving section of the factory. The environment examined was the relative humidity (%), WBGT, air temperature and radiant temperature (°C) of the surrounding workstation area. The environmental factors were measured using Babuc apparatus, which is capable to measure simultaneously those mentioned environmental factors. The time series data of fluctuating level of factors were plotted to identify the significant changes of factors. Then thermal comfort of the workers was assessed by using ASHRAE thermal sensation scale by using Predicted Mean Vote (PMV). Further Predicted Percentage Dissatisfied (PPD) was used to estimate the thermal comfort satisfaction of the occupant. Finally the PPD versus PMV were plotted to present the thermal comfort scenario of workers involved in related workstation. Results: The trend of relative humidity curve from the graph also indicated the increasing level of discomfort. The radiant temperature observed seems consistent during the study while there was decreasing of WBGT start from afternoon due to the rain. The study revealed that the PPD value of 54% of the workers population at the workstation are likely to be satisfied with thermal comfort at this station while the PMV index from ASHRAE indicated the value 1.07-1.41. Conclusion: The empirical study from the PPD and PMV index indicated that workers working at this were influenced by the heat. The less of PPD value from 80% of the population satisfied with the thermal comfort showed the environment factors that were not good for worker while the PMV index showed the area of work is slightly warm.

The UnMousePad

Recently, there has been great interest in multi-touch interfaces. Such devices have taken the form of camera-based systems such as Microsoft Surface [de los Reyes et al. 2007] and Perceptive Pixel's FTIR Display [Han 2005] as well as hand-held devices using capacitive sensors such as the Apple iPhone [Jobs et al. 2008]. However, optical systems are inherently bulky while most capacitive systems are only practical in small form factors and are limited in their application since they respond only to human touch and are insensitive to variations in pressure [Westerman 1999]. We have created the UnMousePad, a flexible and inexpensive multitouch input device based on a newly developed pressure-sensing principle called Interpolating Force Sensitive Resistance. IFSR sensors can acquire high-quality anti-aliased pressure images at high frame rates. They can be paper-thin, flexible, and transparent and can easily be scaled to fit on a portable device or to cover an entire table, floor or wall. The UnMousePad can sense three orders of magnitude of pressure variation, and can be used to distinguish multiple fingertip touches while simultaneously tracking pens and styli with a positional accuracy of 87 dpi, and can sense the pressure distributions of objects placed on its surface. In addition to supporting multi-touch interaction, IFSR is a general pressure imaging technology that can be incorporated into shoes, tennis racquets, hospital beds, factory assembly lines and many other applications. The ability to measure high-quality pressure images at low cost has the potential to dramatically improve the way that people interact with machines and the way that machines interact with the world.

An Effective Scheduling Approach for Maximizing Polyimide Printing Weighted Throughput in Cell Assembly Factories

Polyimide printing (PI) is an important process operation but also often the cause of bottlenecks in capital-intensive cell assembly factories. Therefore, the development of an effective scheduling method to maximize throughput in this PI process is essential and difficult. In the polyimide printing scheduling problem (PISP), jobs are given weights and clustered by their product types, which must be processed on identical parallel PI machines. The setup times for two consecutive jobs between different product types in the PI machines are sequence-dependent. In this paper, the PISP is formulated as a mixed integer linear programming model. The PISP is also transformed into a multiple tour maximum collection problem (MTMCP), a well-known network problem which has been investigated extensively. Based on this transformation, one can therefore solve the PISP near-optimally using the efficient algorithm.

Pulmonary effects of spot welding in automobile assembly

Spot welding is a type of resistance welding in which pieces of metals are pressed together and an electric current is passed through them. Spot welders are at risk of contact with some potentially hazardous agents but there are few studies about the respiratory effects of spot welding. Our objective was to study lung function and respiratory symptoms among spot welders and office workers at an automobile assembly factory in Iran. This was a cross-sectional study of 137 male spot welders and 129 office workers. We used a questionnaire to record demographic data, smoking habits, work history and respiratory symptoms. Spirometry was performed to assess lung function status. Metal fume samples from the respiratory zone of spot welders were analysed. The concentrations of metal fume were less than the American Conference of Industrial Hygienists (ACGIH) threshold limit values. There were significantly lower values for average forced expiratory volume in 1st second (FEV(1)), FEV(1)/forced vital capacity and 25-75% forced expiratory flow in spot welders compared to controls. There was also a significantly raised prevalence of respiratory symptoms (sputum and dyspnoea) in spot welders. Fifteen per cent of spot welders and 1% of controls had an obstructive pattern in spirometry. Our survey suggests that spot welders are at risk of developing respiratory symptoms and decreasing pulmonary function values despite their exposure to components of welding fume being within ACGIH guidelines.

시뮬레이션을 이용한 블록조립 공정 능력 분석

A capacity calculation and process analysis is a very important part for the entire ship production planning. Ship`s production plan is set up with a concept that the product is produced based on the capacity achievable by the processes while general manufacturing sets up the production plan based on product lead-time. Therefore, in case the calculation of capacity for each process of shipbuilding yard is different from actual conditions, a series of production plan - ship table composition, dual schedule plan and execution schedule plan, etc - may accumulate errors, lose reliability of planning information and cause heavy cost deficit in this course. In particular, in case of new shipbuilding yard, stocks between processes are built up and half blocks are not supplied in timely manner, and that is sometimes due to the clumsiness of the operator but it is more often because of the capacity to execute each process is not logically calculated. Therefore, this paper presents the process to calculate the assembly leadtime and assembly process capacity for shipbuilding yard assembly factory. This paper calculated the block type for calculation of assembly lead time based on block DAP(detailed assembly procedure), and introduced cases that calculate production capacities by assembly surface plate by considering the surface plate occupied area of the blocks that change depending on assembly field area and assembly processes through assembly simulation.