RAM represents reliability, availability, and maintenance, and is a key performance indicator that is utilized throughout the life cycle of the weapon system from the stage of requesting to disposal. If the RAM target value is set to a too high value, development may be delayed or development cost may be increased. If it is set to a too low value, frequent failures may occur during training, or a problem may arise that the number of available weapon systems is insufficient. The currently most used method to set the RAM target value is to write an operation mode summary and calculate it through an equation. However, as the definition of the operation mode is not standardized, different RAM target values may be set depending on the authoring organization. This study aims to analyze the current situation and suggest an alternative to this problem.