Productivity Improvement in the Denim Industry by DMAIC Methodology

Productivity Improvement in the Denim Industry by DMAIC Methodology Muhammad Owais Raza Siddiquia, Imran Noorb, Muhammad Dawood Husainc, Muhammad Usama Nooranid, Allah Dade, Waqar Iqbalf, Danmei Sung, a,b,c,dNED University of Engineering & Technology, Department of Textile Engineering, University Road, 75270, Karachi, Pakistan. a,gHeriot-Watt University, School of Textiles & Design, TD1 3HF, Galashiels, UK. ePakistan Institute of Fashion and Design, Lahore, Pakistan. fTiangong University, School of Textile Science and Engineering, Tianjin, China, Email: [email protected] The aim of this paper is to boost productivity improvement by reducing the rejection rate and finding ways to improve the quality of the textile (denim) industry. The methodology used here is based on Six Sigma, which aids as a catalyst for lowering the rejection rate in the denim industry. Six Sigma in this paper serves as a systematic tool for continuous quality process improvement and for achieving desired targets and quality. The DMAIC model provides a framework that ultimately decreases the variation in the process, and executes a central plain that would be readily accepted by the organisation and which encourages people to adapt it. In the defining phase, the root causes of the problem and faults were recognised. As a result, a broken end was found to be the main cause of the rejection of defective products. The root causes were analysed using a cause and effect diagram. In the improvement phase, the design of the experiment (DOE) was implemented, and key parameters of the process were set up. This revealed that high concentrations of acid and hydrogen peroxide are the core origin of the diminishing yarn strength in the back process. A factorial design, with two replications, was performed. Hydrogen peroxide and acid were used in the dyeing department as chemical oxidation for indigo dye. After the implementation of Six Sigma, the productivity of the company improved and the rejection rate was reduced.