This research paper focuses on process improvement carried out in the nacelle unit of a wind turbine manufacturer. Lean Manufacturing (LM) is implemented to improve productivity in terms of manufacturing throughput time and to also reduce cost of rework/manufacturing costs. Tools like Root Cause Analysis and Kaizen were used in conjunction to create efficient results for the manufacturing processes. By assessing the current condition and establishing a baseline to work upon, improvement was achieved through the testing and implementation of solutions to the problems found. Process improvement was successful as seen in the acceleration of schedules and reduction in costs.