During the collective bargaining process, when parties fail to reach agreements about the terms and conditions of employment, either side can typically make it known that they have reached an impasse, signaling that they are unable to resolve their differences on their own.

The grievance process is one method of resolving disputes between workers and their employers, usually in the context of a collective bargaining agreement. 

The term collective bargaining refers to contractual negotiations between employers and groups of employees to determine specific conditions of employment. 

A closed shop refers to a business or organization in which all employees are required to become union members as a precondition of employment.