A quality management system (QMS) is a formalized system that documents processes, procedures, and responsibilities for achieving quality policies and objectives. A QMS helps coordinate and direct an organization’s activities to meet customer and regulatory requirements and improve its effectiveness and efficiency on a continuous basis.   
ISO 9001:2015, the international standard specifying requirements for quality management systems, is the most prominent approach to quality management systems.
While some use the term QMS to describe the ISO 9001 standard or the group of documents detailing the QMS, it actually refers to the entirety of the system. The documents only serve to describe the system.
Quality management systems serve many purposes, including:
Improving processes
Reducing waste
Lowering costs
Facilitating and identifying training opportunities
Engaging staff
Setting organization-wide direction
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