Combat Fabber Asistance

Hey everybody i got a little question here. I've seen this so often that aa combat fabber assisted in multiple factorys. I actually don't know how u give the order for that i just know how to send him to one factory or giving repair order in a circle on those factorys but then he only assists them once and then he stops. Could anybody pls tell me how u give the combat fabber the order to assist multiple factorys forever?

Use the area command and turn the repeat option on.

Or just have a combat fabber stand next to the factories. It'll assist automatically.

*duh* lol... for some reason I thought the fabber only auto repaired rather than assisted construction, so I've been wasting clicks in games when I didn't need to