The application of Six Sigma to Process Improvement
As requested in the quality homework, an article “Application of Six Sigma Methodology to Reduce Defects of a Grinding Process”  was studied. In the case from this article, an Indian automotive company was suffering from a high rejection rate for a certain piece (distance piece) in a component (fuel injector), which requires precise fine grinding to ensure good functioning of the injector. Due to the large amount of production rate of the pieces, it’s not practical to carry out 100% inspection. However the rejection rate was very high and the piece played a critical role in the whole component, thus it is an ...view middle of the document...
Due to success in this project, the management decided to use the six sigma method for all future improvement initiatives. For monitoring of six sigma initiatives, a core group was formed with all functional heads of the organization. The responsibility of this team was selection of projects and monitoring the execution of project. All issues related to implementation were also reported to this team for further action. Thus, Six Sigma was introduced as a system in the organization to address any type of problems in the processes. The ultimate objective of the management was to bring a cultural change in the organization by involving everyone in the organization in this movement towards excellence.
Identifying improvement project
The first step towards solving any problem in the Six Sigma method is by formulating a team of people associated with the process. The team selected for this project includes the Senior Manager—manufacturing as the Black Belt (BB). The other members of the team were Planning Manager, Maintenance Manager, Quality Control Senior Engineer and one Machine Operator. BB acts as the team leader, and was responsible for the overall success of the project. In this particular project, BB himself was the process owner. The primary responsibility of team members was to support BB in executing the project-related actions. The Head of manufacturing department was identified as the Champion and the Head of Business Excellence department as master black belt (MBB) for this project. This creates a common vision and sense of ownership for the project, so that the entire team is focused on the objectives of the project.
The team had several meetings with the Champion and MBB to discuss various aspects of the problem, including the internal and customer-related issues arising because of this problem. The team decided to consider the rejection percentage of distance pieces after fine grinding process as the Critical to Quality (CTQ) characteristic for this project. The goal statement was defined as the reduction in rejection of distance pieces by 50% from the existing level, which should result in large cost saving for the company in terms of reduction in, rework and scrap cost.
The CTQ considered in this case was the rejection percentage of distance pieces after the fine grinding process. These rejections were mainly due to the occurrence of different types of defects, such as burr, shades, deep lines, patches and damage, on the component after machining. Since there was no instrument involved in the inspection process and only visual inspection was performed, before going ahead with further data...