What is the "proficiency" of DNF personal information? What's the use? How to rise?

When using equipment drawings to make equipment, the proficiency of making equipment will increase, and the higher the level, the higher the probability of making high-strength equipment. For example, the equipment you make when you are proficient in 0 is basically +5, and the equipment you make when you are proficient is +8 +9, and it will be higher+12+13, but the equipment proficiency of each equipment is the same as him.