Scrap Rate Reduction for a High-Volume Aerospace Bearing Ring Using DMAIC Methodology

To remain competitive within the marketplace, manufacturing companies must seek out opportunities for increased profitability and quality in their production. In order to accomplish these business objectives, efficiency in identifying and solving problems on the production floor is critical. Delays in this process can produce disastrous impacts to the manufacturing plant’s bottom line. The DMAIC process, the core to the Lean Six Sigma methodology, is a logical step-by-step process designed to achieve this goal. The DMAIC methodology is applied to resolve an observed high scrap rate of a high-volume bearing ring component. The baseline performance of the process was measured using descriptive statistics and process capability analysis yielding Cp and Cpk values of 0.311 and 0.175, respectively. Pareto analysis highlighted 80% of defects were the result of casting defects, undersized outer diameter, and parallelism errors on the bearing ring. Through ideation and a weighted scoring model, the design and implementation of new tooling was a solution to resolve the diameter and parallelism issues. Failure Modes and Effects Analysis was applied to mitigate any risks of the proposed solution. Implementation of the solution conflicted with manufacturing priorities, however, future work is proposed to determine the effectiveness of the solution. Keywords Bearings, Manufacturing, Aerospace, DMAIC, Lean Six Sigma