Today industrial companies are subject to major and profound changes. It is constantly confronted with a world of ruthless competition that continually aims to improve quality, cost, and lead time. Each company works to satisfy the requirements of its customers and to do this, it continually improves its performance and controls its manufacturing processes from the reception of raw materials from the suppliers to the shipment of the final product to the customer. In this paper, the study focuses on the assembly area of an electrical wiring harness production line and adopts a Lean Manufacturing approach to reduce the time waste and improve the efficiency of this line of engine wiring harness using Line balancing and the work allowed an eliminate of Waiting Muda and increase the efficiency.