This study aims to reduce the waste surplus (defects) in the production process of agricultural machinery parts in the production process of Collar A tractor parts by using the Pareto chart to find significant problems. After that, the root cause of the problem is analyzed using a fishbone diagram, and why-why analysis leads to the root cause utilizing ECRS principles for correction to help improve processes. Based on current research, defect data from the past three months was collected. The main problem is that with a diameter of 40.5 over spec, the average defect proportion is 53%. Therefore, after ECRS improvement using the R: Rearrange principle, modify the workflow, to eliminate the loss that occurs in the production process, resulting in the proportion of waste reduced to only 1 percent.