Weakest link

Weakest link is a term that has its origins in a well-known proverb. We will examine the meaning of the term weakest link, where it came from and some examples of its use in sentences.The weakest link is the person or point in a process that is the most vulnerable, laziest, most incompetent or least […]
from Grammarist
http://grammarist.com/usage/weakest-link/