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This paper presents the use of mathematical modeling for developing a multi-stage manufacturing process of producing a blank for a bellows unit reinforcement ring made of VT6 (Ti-6Al-4V) alloy. The paper studies the influence of the main process parameters on the formation and distribution of the proportion of globular microstructure over the blank cross-section. The change of form was determined using a finite element model of plastic deformation. The phase transformation kinetics was determined using the Johnson-Mehl-Avrami-Kolmogorov equation. [ABSTRACT FROM AUTHOR]

In a labor intensive manufacturing system, optimal operator allocation is one of the most important decisions in determining the efficiency of the system. In this paper, ten operator allocation alternatives are identified using the computer simulation ARENA. Two inputs; average wait time and average cycle time and two outputs; average operator utilization and total packet values of each alternative are generated. Four Data Envelopment Analysis (DEA) models; CCR, BCC, MCDEA and AHP/DEA are used to determine the optimal operator allocation at one of the SME food manufacturing companies in Selangor. The results of all four DEA models showed that the optimal operator allocation is six operators at peeling process, three operators at washing and slicing process, three operators at frying process and two operators at packaging process. [ABSTRACT FROM AUTHOR]

The BBMCSFilter method was developed to solve mixed integer nonlinear programming problems. This kind of problems have integer and continuous variables and they appear very frequently in process engineering problems. The objective of this work is to analyze the performance of the method when the coordinate searches are interrupted in the context of the multistart strategy. From the numerical experiments, we observed a reduction on the number of function evaluations and on the CPU time. [ABSTRACT FROM AUTHOR]

A manufacturing process of erbium doped fibre amplifiers is complicated. It needs to meet the customers' requirements under a present economic status that products need to be shipped to customers as soon as possible after purchasing orders. This research aims to study and improve processes and production lines of erbium doped fibre amplifiers using lean manufacturing systems via an application of computer simulation. Three scenarios of lean tooled box systems are selected via the expert system. Firstly, the production schedule based on shipment date is combined with a first in first out control system. The second scenario focuses on a designed flow process plant layout. Finally, the previous flow process plant layout combines with production schedule based on shipment date including the first in first out control systems. The computer simulation with the limited data via an expected value is used to observe the performance of all scenarios. The most preferable resulted lean tooled box systems from a computer simulation are selected to implement in the real process of a production of erbium doped fibre amplifiers. A comparison is carried out to determine the actual performance measures via an analysis of variance of the response or the production time per unit achieved in each scenario. The goodness of an adequacy of the linear statistical model via experimental errors or residuals is also performed to check the normality, constant variance and independence of the residuals. The results show that a hybrid scenario of lean manufacturing system with the first in first out control and flow process plant lay out statistically leads to better performance in terms of the mean and variance of production times. [ABSTRACT FROM AUTHOR]