The application of operational risk management is conducted in this research to control operational risks for motorcycle parts factory. This research has developed from the risk identification within manufacturing process of 3 groups of product, Sprocket Gear, Collar and Meter Gear from process of Raw Material Preparation, Machining, Gearing, until Grinding. Then, the risk analysis and evaluation has been applied to classify those risks into 4 levels. This research has determined the treatment for managing the high and emergency risks which named as major risk events. The study mainly used the Fault Tree Analysis (FTA) as the technique for analyzing the root cause of risks. Base on the study, it was found that there were 4 groups of failure that impact to product quality. They include 1) Misleading if measurement from human error 2) Diameter and Shape failure from machine error 3) Material changing from material specification 4) Roughness error from inappropriate method. Those failures led to root of causes of those 12 major risk events. Consequently, those 12 major risks had an effect to the number of defects that over company’s targets. The risk treatment plan had been established for mitigation those major risks. Those plans include training, preventive maintenance, skill evaluation, In-process of quality control, working standard, and check sheet. From the monitoring and evaluation after implementation, the result is that the improvement of defects has been reduced from 25,077 pieces to 22,943 pieces, or to 8.51 percent. In aspect of Risk number, the percentage of Risk Number from 4 processes comparing between before and after implementation has been decreased to 54 percent.