Productivity and Quality in Smart Manufacturing Systems

Defect Analysis of Power Transformers Tank Using The Six Sigma Approach in Tank Fabrication

Nur Aswan Darwis and Moses Laksono singgih


A transformer is an integral part of the reliability of the electric power system in Indonesia. Loss of work on the transformer can cause Power system failures due to problems with the quality of the transformer tank itself. Based on data from one of the Tank Fabrication customers, namely Transformer Fabrication, there are tank quality discrepancies, and there has been no severe repair to resolve the problem. Bad quality of the tank cause leakage and the appearance of rust, so that it will affect the quality of the transformer as a whole. There are many defects in the results of internal inspections, so process improvements are needed. The problems should be analyzed more deeply. Inconsistency in a quality necessitates the need for an effective and efficient improvement method. According to a priority scale, the Six Sigma approach method is a systematic improvement method to parse problems and solve them. Tank Fabrication sigma level based on customer complaint data is only 2.76. Based on complaint data from Transformer Fabrication, the most dominant problem comes from the welding and painting process, namely 77.1%, where under spec painting thickness defects are the most prevalent, followed by welding defects in the form of incomplete fusion, porosity, and spatter. The identification results can be a point where Tank Fabrication improves the production process to reduce customer complaints. The company can reduce rework costs, the company’s sigma value will increase, and customer confidence will be better.

Keywords: Tank, transformer, pareto, six Sigma


Scroll to Top