Application of Six Sigma Methodology in Glazing and Printing Processes: The Case of Lanka Wall Tiles PLC

Six Sigma is a data-driven process of thinking to create new knowledge and skills for business process improvement. It is a buzz word in the business community today as Six Sigma thinking has gained widespread popularity as a part of business process improvement methodology. This paper presents the results of applying Six Sigma methodology at Lanka Wall Tiles PLC in the areas of glazing and printing operations. The company in its process re-engineering project identified glazing and printing operations as the main processes in which defects occur regularly. In order to address the issue of production defects a five-step DMAIC framework, viz. Define, Measure, Analyze, Improve and Control, was applied. In the define stage, the size of the problem was gauged after mapping the process by means of the SIPOC (Supplier, Input, Process, Outputs, Customer) model. In the measurement and data analysis stages, a set of carefully chosen statistical methods and problem solving techniques of Six Sigma system were applied to uncover the sources of variations (SOV). Data was collected from both the past records of production and by observation of the process for a period of 21 days. Data analysis was done using tools and techniques such as quality function deployment (QFD), control charts, cross tabulation, cause and effect diagrams and Pareto charts. A detailed analysis of the data revealed the major sources of variations for which homegrown solutions were found and implemented by the project team at the improvement stage. A cautious application of DMAIC over a period of two months resulted in a gradual and steady reduction of defects by a significant 3.3 percent giving rise to savings of approximately LKR 3.36 million per month for the company. It further revealed that the methodical and systematic application of the Six Sigma system using the thinking process of DMAIC enabled the team to identify sources of variations that had been undetected for a long period of time. The success of the experiment paves the way for further studies as well as the application of Six Sigma methodology in the manufacturing environments of all production units of the company.