Mahmut Kayar

Heuristic production line balancing problem solution with MATLAB software programming

Purpose The purpose of this paper is to find the most efficient assembly line balancing solution across many heuristic line balancing methods, in assistance with a developed computer program. Design/methodology/approach In this paper, assembly line balancing problem was analyzed using t-shirt and knitted pants data. A computer program using MATLAB software for the solution of assembly line balancing problems has been developed. In this study, following heuristic assembly line balancing methods were applied: Hoffman method; position weight method; COMSOAL method; and Kilbridge and Wester method. A MATLAB program has been developed by taking into account of theoretical solution of all these methods. Later the program is developed further by analyzing solutions made manually and is made to verify the developed program. Findings Pre-studies which were conducted in order to decide which programming language would be the best choice for line balancing methods’ application came out with the result that MATLAB, from between C, C++, C# and Java, would be the best software choice. The main reason for this choice is that MATLAB is a powerful matrix operation software with a powerful user interface designing tool and has the tools to make development program to be used universally in every computer. Originality/value When the researches were investigated, it is clearly seen that, this study is the first research on using computer program for solving assembly line balancing problem.

Comparing Heuristic and Simulation Methods Applied to the Apparel Assembly Line Balancing Problem

Marmara University, Faculty of Technology, Department of Textile Engineering, Istanbul, Turkey E-mail: mkayar@marmara.edu.tr Abstract In this study, general information on assembly line and simulation and researches on assembly line balancing are theoretically analysed. Afterward time studies with respect to blouse production, which will be analysed in assembly line balancing, are conducted and information, which is necessary for assembly line balancing, is obtained. In parallel with the data obtained, the assembly line is firstly balanced by the Hoffman method, which is one of the heuristic methods. Then the assembly line is balanced again using the Arena Simulation program and results which belong to two different assembly line balancing resolutions are given. The aim of the study is to create an assembly line which has highest line efficiency by using an optimum number of machines and operators as well as highlight the applicability of the Hoffman method to ready-to-wear assembly lines.

Effects of perfume on mechanical and color properties of cotton fabrics

Purpose – The purpose of this paper is to examine the effects of perfume on cotton fabrics and satisfy the perfume user’s curiosity on this issue. Design/methodology/approach – In this study, the selected perfume was applied on woven and knitted cotton fabric samples in order to investigate the effects of perfume on mechanical and colour properties of the fabrics. For this purpose the chosen perfume was applied in two different amounts (four spraying and eight spraying) from the same distance to the fabric surface. Then the fabric samples were left for 24 hours in order to fulfill the daily usage conditions. Samples were evaluated in terms of tensile strength, pilling and abrasion tests, respectively. Colour measurement test was performed for investigating the fading effect of the perfume and FTIR analysis was carried out for examining the chemical changes. Findings – Result of the study revealed that perfume did not have any effects on tensile strength properties of cotton knitted and woven fabrics and c...

Study on Importance of Employee Performance Assesment and Lost Productive Time Rate Determination in Garment Assembly Lines

This study primarily includes theoretical information on the performance and lost productive time of a firm. Furthermore t-shirt sewing operations of a garment firm were analysed and time measurement for each operation was carried out by the time keeping method. By considering the measurements obtained, different performance estimations, the firm’s lost productive time rates, and the standard time was calculated within 5 different scenarios. According to each sewing standard time obtained, the assembly line balancing practice was carried out using the Hoffman method. Later on results of the assembly line balancing were compared, and the importance of employee performance assessment and its lost productive time rates for firms were discussed. The aim of the study was to emphasize the value of impeccable determination of the employee performance assessment and lost productive time rates. Consequently garment firms will be more cautious in calculating the standard time and will be able to reach their production target within the accurate measurement they obtain.

Analysing effect of the factors on ultrasonic seam tensile properties of nonwoven fabrics by Nested Anova Design

Purpose – The purpose of this paper is to investigate the factors effecting ultrasonic seam tensile properties. Design/methodology/approach – In this study, 100 percent polypropylene and 100 percent polyester spunbond and meltblown nonwoven fabrics were sewn by using ultrasonic sewing machine with different rollers which have two, three and four rows. Seam tensile properties of the sewn nonwoven fabrics were investigated. Four-Level Nested Anova Design was applied to the data by using Minitab 15 software program. Findings – Higher seam strength values were obtained by using four rows roller, PP fiber, spunbond fabric and 50 g/m2 fabric area density for all nonwoven fabrics. Statistical significance was found between fabric area density, roller rows and seam tensile strength properties and between fabric type, roller rows and seam elongation at break values. Originality/value – When the authors look at the studies related to ultrasonic sewing, several researchers studied on welding parameters of ultrasonic...