A Complex Garment Assembly Line Balancing Using Simulation-based Optimization

Abstract

The nascent wave of disruptive competition in the current business environment brought about by the fourth industrial revolution (Fashion 4.0 or Apparel 4.0) is enormous. Therefore, it is paramount important to apparel industry to be flexible enough to respond quickly to the unstable customers' demand through continuous improvement of their process efficiency and productivity. This study aims at achieving an optimal trouser assembly line balancing using simulation-based optimization via design of experiment. The empirical study is conducted at Southern Range Nyanza Limited (NYTIL) garment facility and a complex trouser assembly line with 72 operations is considered. The discrete event simulation of the trouser assembly line is developed using Arena simulation software. The local optimal solution is obtained from simulation experimentation and is adopted for the optimization process. The OptQuest tool is utilized to solve a single objective function (throughput) optimization problem.The results show that average throughput increases from the existing design (490 pieces per day) to local optimal design (638) and global optimal design (762). Consequently, the line efficiency increases from 61.2% to 79.7% to 95.2% respectively. The high increase in line efficiency and average throughput confirms the suitability assembly line balancing using simulation-based optimization via design of experiment.

Simulation Metamodeling Approach to Complex Design of Garment Assembly Lines

“…This is because adding the resource in the bottleneck workstation reduces both cycle time and work in progress (WIP). In spite of the fact that the metamodel was not used for further model prediction, the present study found it most suitable for inference [19] and initial solution (local optimal) for optimization process [37]. The inference was drawn from the regression metamodel to analyze the factors' effects on the production throughput.…”

“…Therefore, the simulation model was well-developed and run smoothly without freezing the 64 bits notebook computer with a 2.00 GHz Intel core i3 CPU and 4.00 GB RAM. In this respect, the computer modeling of preparatory sections of trouser assembly line including front and back were done separately and then combined using Arena Match modules to form one complex trouser assembly line [34]. The main trouser assembly line sections include main body assembly (MBA), front (FP), back (BP), big loop preparation (BLP) as well-illustrated in Figure 4.…”

“…This results into development of different simulation models as known as design scenarios or design alternatives. Therefore, 16 design alternatives were created from the simulation experiments [34]. Experiments run were performed for each design alternative while observing their mean throughput as shown in the Table 3.…”

Simulation metamodeling approach to complex design of garment assembly lines

“…Therefore, three elements from the Arena project bar including basic process, advanced process and transfer were used. For further understanding of the simulation model of the trouser assembly line, the constructed Arena simulation model (base model) is deposited at https://doi.org/10.17632/T5W96KH5W7.1 [47].…”

“…The base simulation model was altered depending on 16 design points generated from the design of experiment. Therefore, 16 design scenarios were created from the simulation experiments (https://doi.org/10.17632/T5W96KH5W7.1) [47]. Experimental runs were performed on each design scenario while observing the mean throughput (Table 3).…”