A process improvement study with lean 6 sigma applications in a wheel molds manufacturing company

Companies in the automotive industry work in global competitive conditions where customer demands are constantly changing, model changes are rapidly increasing, and production quantities are decreasing. With globalization, the automotive industry also produces small batches rather than large batches. While the lifespan of parts in the automotive industry used to be 5 years, it has now decreased to 2-3 years. The companies must be agile and adapt to innovations quickly. For this reason, the companies in the automotive industry and/or sub-industry must develop various strategies to make more sales in a competitive environment. Among these strategies, increasing model diversity, increasing project commissioning speeds, and producing higher quality, environmentally friendly, and cost-effective products in a shorter time have an important place. This thesis aims to provide a cost advantage by reducing mold production times and consumable costs for the company where the application is carried out, and to present a comprehensive study to the literature on how Lean Six Sigma stages can be applied. It is also aimed to increase the capacity, increase the amount of output produced per unit time, and improve the project costs by using the DMAIC (Define, Measure, Analyze, Improve, Control) cycle. In this context, the SIPOC (Supplier, Input, Process, Output, Customer) diagram, tree diagram, cause-effect matrix, statistical analyses, and value stream maps were prepared, and various improvements were presented. It is predicted that with an effective Lean Six Sigma application, operating costs in mold production processes will decrease, production times will shorten, error rates will decrease, and so, performance will increase. As a result of the applications, it was determined that there was an improvement of 4,60% in total capacity, a 14,29% reduction in mold production time, and a 7,15% saving in overall consumable and external labor costs. Thus, waste can be reduced, and a simpler and more efficient production system can be created. The applications and results obtained can be used as a guiding resource for Lean Six Sigma projects of companies operating in similar sectors.