Defect reduction and control based on application of process control
Date of Issue2010
School of Mechanical and Aerospace Engineering
Singapore-MIT Alliance Programme
This thesis addresses the defect reduction and control in a printing process at a food packaging company now experiencing hundreds of printing defects. Methodologies of Define, Measure, Analyze, Improve, and Control (DMAIC), and Response Surface Model were introduced to reduce the defect rate and control the process. As a result, critical inputs were identified, and a set of statistical regression models were constructed to predict the flaw size and its variance by knowing the critical inputs of the process. The mathematical optimal settings were determined to minimize the flaw size and its variance. Moreover, advanced control charts, and detailed Out-of-Control-Action-Plans (OCAP) were developed to monitor and control the process.