Lean Six-Sigma applications in aircraft assembly

Abstract

To improve the performance of a process and ensure on time delivery there are numerous different approaches available nowadays. Lean offers a unique method that helps identify possible improvement areas on a production line. Also Six-Sigma offers a unique approach that is widely used in industries in order to improve the process and thereby reduce the number of defects. The lean approach can be used to reduce or even eliminate waste and thereby ensure on time delivery of products. A Value Stream Map (VSM) is one of the main tools of lean manufacturing that can be used to represent the flow of material and information in a production line. It can be utilized to identify areas where improvements can be incorporated for a smooth flow of products. DMAIC (Define-Measure-Analyze- Improve-control) is a five-step approach that utilizes different Six-Sigma tools to generate ideas, collect and measure data, analyze and come up with improvement plans to improve the process under study. Lean manufacturing concepts can be used to identify waste from the customer point of view and eliminate them. Lean cannot bring a process under statistical control. On the other hand, six-sigma cannot dramatically improve process speed or reduce cost. The integrated lean six-sigma approach maximizes shareholder value by achieving the fastest rate of improvement in customer satisfaction, cost, quality, process speed, and invested capital. In aircraft industries, the phenomenal increase in demand has pushed the manufacturers to look for new concepts to stay in business amidst strong competition. A new methodology of lean six sigma integration was proposed and tested in an aircraft industry. The study involves the assembly of the upper main entry door of a business jet. Improvement opportunities were identified from a high-level value stream map. The DMAIC approach was utilized to address the identified opportunities for improvement. The results indicate that the lead-time was reduced from 26 to 10 days. Using appropriate statistical tools and by incorporating standard engineering changes the occurrence of non-conformance was reduced by 30%. This resulted in a reduction of rework time by 3 hours per aircraft and accounted for close to $6000 of savings.