In this research, lean techniques were utilized in a wood plastic composite manufacturer to eliminate waste of the production system. Measurements showed the production capacity of the factory was limited and had a lot of waste in many processes, so customer demand could not be met. Improvement of the real production line would be complex and may cause interruption in production. Therefore, computer simulation was used to show the system performances before and after improvement. Lean techniques such as Eliminate, Combine, Rearrange and Simplify (ECRS) , quick setup, Computer Aided Engineering (CAE) , and line balancing, were employed to eliminate waste and shorten cycle time. After improving by lean techniques, the result showed very high productivity, utilization, efficiency and profit. However, the capacity still did not reach the demand target. So, Theory of Constraint (TOC) with bottleneck consideration and optimization were utilized to identify the suitable resources of the system to achieve high performances and customer satisfaction.
