Quality improvement with PDCA approach and design of experiment method in single socks industry in Indonesia

Abstract

The apparel industry, especially the knitted socks industry and the like, has experienced a decline in production. This is because there are still many production defects that are produced. Some sock industries have similar processes so that the most dominant defect is in the knitting part. This study aims to analyze the factors that cause the main weakness in socks and propose an effort to correct the chief defect, namely a hole in the single type of socks. The method used in repairing this defect is the Design of Experiment (DoE) method with the Plan-Do-Check-Action (PDCA) approach. The PDCA approach is one approach method to help improve the quality of production ongoing basis in line with the management framework. The results of this study, it was found that the factors causing the dominant defect were the linking needle did not match at 504 RPN, the yarn hardness varied by 441 RPN, the thread clumps in the cutter were 384 RPN, the socks were checked directly into the plate at 294 RPN. The improvement efforts are included in the Standard Operational Procedure (SOP) so that all corrective actions can be documented and socialized to employees. The results of the DoE found the best variable composition or optimal parameters obtained, namely new needle type and hardness yarn scale 55. At the same time, improvement defects can reduce defects before improvement is 11.08% and after improvement is 5.54%. The practical implications of the results of this research can be used to reference those interested in researching the same or similar problems.