ISO 9001 defines the criteria for a quality management system (QMS) which can be used by any organization, large or small, regardless of its field of activity. In fact, there are over one million companies and organizations in over 170 countries certified to the requirements of ISO 9001. 

With its roots going back to the U.S. Department of Defense MIL-Q-9858A, this standard is based on a number of quality management principles including a strong customer focus, the motivation and implication of top management, the process approach and continual improvement. 

Using ISO 9001 helps ensure that customers get consistent, good-quality products and services, which in turn brings increased business. 

The Seven Principles of ISO 9001:2015
The Seven Principles of ISO 9001:2015 (source: ASQ.org)