06-11-2014, 11:58 AM
Abstracts: Six Sigma is a business management strategy, first developed by Motorola in 1986, which seeks to improve the quality of process outputs. It identifies and removes the cause of Defects and minimizes variability in manufacturing and business Processes. A set of quality management methods and statistical methods are used. Each Six Sigma project carried out within an organization follows a defined sequence of steps and quantified financial targets. According to the definition, a Six Sigma process is one in which 99.99966% of the products manufactured are statistically expected to be free of defects (3.4 defects per million). Six Sigma uses a group of improvement specialists for problem solving and improving the process continuously. Six Sigma techniques have two main methodologies DMAIC and DMADV. Define Measure, Analyze, Improve, and Control (DMAIC) methodology was followed for reducing the rework. The reasons for the main problem can be detected using again two methodologies FTA and failure mode and effects analysis. FTA deals with identifying all possible causes related to a particular problem. It is a stepwise approach to identify causes and all the parameters related to every cause. It can be used in almost every application which involves cause-effect analysis. Once the problem is defined, it is to be measured so as to collect statistical data about the problem. Once the statistical data is collected, it is analyses during various analysis techniques like chi-square test. Mini tab statistical software was used for the analysis of various phases of the project. The casted engine block is processed with operations like rough boring, water clearance chamfer, surface milling, and finish boring and so forth before accomplishing the engine assembly. Critical operations which demand precise dimension control are performed on special purpose machines. Engine block boring is one of the critical operations performed on special purpose machines under study.