1. Data analysis ability (at least be able to understand weekly weight index, and shift arrangement, seasoning, work target and whether there is any abnormality depend on this data)! 2. Market analysis ability (if you have this, you will have it, if you don't have it, you won't have it, will you come or not)! 3. Also, there are different eyes, jewelry is not just jewelry! You can ask if you don't understand. Otherwise, use it.