The optimization design of uniform’s hanging production line
Authors: Cui Huirong , Yan Yinong 
Published: May 2015

Purpose
– Garment manufacturing is a traditional industry with global competition. The most critical part is streamline, as it generally involves a great number of operations. The purpose of this paper is to, based on the model of group technology (GT), sum up the methods of assembly line optimization to optimize the streamline, so that the machines of the workstation can perform the assigned tasks with a balanced loading.

Design/methodology/approach
– In this paper, the methods of obtaining and optimizing data includes literature, research and optimization methods of basing on GT model. The main direction of literature has two aspects: Lean production theory and streamline assignment. Research mainly concludes three aspects: research place, research object and the research content. The method of time determination is averaging the testing values of repeated measurements. Optimization methods of basing on GT model mainly include combination of the same type of technologic processes in sequence, combination of independent branch process, the combination of mainstream and branch processes and offside combination of the same type of processes.

Findings
– After optimization, in the utilization rate of equipment: hanging system ratio was increased from 22.95 to 62.12 percent, which greatly improved the utilization rate of enterprise equipment. In equipment layout: hanging equipment layout was turned linear type into “U” type, which realized the synchronization of production. GT model will be well applied in the garment production streamline. Compared with other enterprises, A company has large garment hanging system, which reflects the advanced, comprehensive, representative. Therefore, the paper applied optimization methods to trousers, production efficiency has been improved greatly, the utilization rate of equipment is promoted and reworking phenomenon is reduced greatly.

Research limitations/implications
– Through the optimization of the production process and equipment layout, the A company’s compiling efficiency has been greatly improved, but how can the system become computerized, accurately and intelligence, which has been an important direction of research now.

Practical implications
– By optimizing, it is fully proved that applying GT to the streamline optimization is feasible. GT is an important branch of Lean production, summing up the optimization methods basing on the GT model to optimize the streamline not only enriches the relevant theory research, but also provides a theoretical basis for the practical production. GT model not only can be used in the shirt production process, as for other production processes, for example, trousers, skirts can also be widely applied, which realizes the theory application in the practical production.

Originality/value
– The originality of this paper is that through the analysis of the model of GT, the paper sums up the methods of assembly line optimization to optimize the streamline. Although the model of GT is used widely in electronics, automobile and industry, it is relatively weak in the optimization of garment production line, there are not many literatures on practical application of group technology in the clothing. Besides, the paper is applied to practical production, which not only can improve production efficiency, but also make the theoretical research have basis and combine the theory and practical production.