Generally there are two methods to do PCB outline, routing and punching.
Routing is suit for those simple boards with simple outline. But it is easy to cause burr on the edge. Also, if don’t make the tooling holes well, the boards may be easy moving while routing, which cause to the outline crooked.-
So, If you need the outline more precision and nice, the best way is to custom a tool for punching, in such way, the outline shape is very exact and no so much burr on the edge. It is used for those boards in big panel with small boards, special outline as well as high precision boards. Punching also can speed up the production lead time. But for such way the cost is expensive than routing.
