The ability to add links between actual parts in my machine model - it was difficult at first but with some effort I could figure out how! It also has an easy way for me as engineer/mechanic not sure if this applies since i am just learning so far its simple enough yet powerful tool which can be used by anyone who knows what they are doing or someone like myself trying their best without any experience whatsoever!! Its really helpful when working towards achieving goals such as reducing downtime due maintenance requirements etc.