What is the process which scientists grade the work of other scientist before published?

The process is called Peer-Reviewing. In Peer-Reviewing, scientists/academic peers "peer review" the work of a scientist to check for accuracy or any false information that might reduce the legitimacy of their study or change "how realistic/real" their study is.

p.s. This is also common sense because scientists make up an entire scientific community who base their scientific studies on consistency and accuracy.