This paper proposed a parallel automated assembly line system to produce multiple products having multiple autonomous guided vehicles (AGVs). Several assembly lines are configured to produce multiple products in which the technologies of machines are shared among the assembly lines when required. The transportation between the stations in an assembly line (intra assembly line) and among station...

Serial measurements of urinary adrenaline, noradrenaline, and 11-hydroxycorticosteroid excretion were performed on 32 healthy men under two conditions of work stress; piecework and work on assembly line. A statistically significant increase in adrenaline, noradrenaline, and 11-hydroxycorticosteroids was observed for piecework and assembly line workers compared with salaried and 'ordinary' worke...

Proper planning of assembly lines is one of the production managers’ concerns at the tactical level so that it would be possible to use the machine capacity, reduce operating costs and deliver customer orders on time. The lack of an efficient method in balancing assembly line can create threatening problems for manufacturing organizations. The use of assembly line balancing methods cannot balan...

A cross-sectional survey of semiconductor factories was conducted to identify the ergonomic risk factors in the work processes, the prevalence of body pain among workers, and the relationship between body pain and work processes. A total of 906 women semiconductor workers took part in the study. In wafer preparation and polishing, a combination of lifting weights and prolonged standing might ha...

In this paper we are to present a practical application of Axiomatic Design (AD) methodology, as a roadmap to lean production, in redesigning a car body assembly line. Axiomatic Design theory provides a framework to simplify the whole problem. According to the AD principles, a hierarchical structure has been developed. The developed structure originated in lean manufacturing principles and exis...

Assembly lines are the most commonly used method for a mass production environment. Their main purpose is to increase efficiency by maximizing the ratio between throughput and required costs. However, in the last few decades, market demands have changed enormously. The emphasis is now on shorter lead times, larger product variety, higher quality and more customized options. At the same time, so...

This paper presents a multi-objective Particle Swarm Optimization (PSO) algorithm for worker assignment and mixed-model assembly line balancing problem when task times depend on the worker’s skill level. The objectives of this model are minimization of the number of stations (equivalent to the maximization of the weighted line efficiency), minimization of the weighted smoothness index and minim...

the musculoskeletal disorders cover a large percent of occupational diseases; therefore, in order to protect workers from such disorders, there is a need to evaluate workers positions at work in different industries. in a major furniture manufacture located in tehran, 500 workers were examined. these workers were divided into fourteen working groups, including production lines of water-heater, ...

The objective of assembly line balancing (ALB) is to minimize the number of workstations organized to perform tasks with precedence constraints. An important element of proper assignment of tasks to workstations is the consideration of skill requirement of tasks, and skill level of workers. Some tasks may require special skills, some workers might not be able to perform complicated tasks, and s...

In this paper, we present an extension to the TSALB problem (Time and Space constrained Assembly Line Balancing) with ergonomic risk restrictions. This ergonomic risk is defined from the task durations and their categories regarding to the risk factor for the workers. A study is presented through a case linked to an engine assembly line in the Automobile industry, considering variable demand.