This applies to not just Boeing and US manufacturers (or even aviation) but to every form of industry since the late 90s and applies to any company with an aerospace ISO9000 accreditation since 1999, including Airbus and other European aircraft and component manufacturers.
The Aviation version of the ISO is Aviation Standard AS 9000 and contains some 50% more requirements than the ISO and also requires compliance with certain supplementary documents.
If you work for an organization where there are no dedicated independent inspectors who physically check each critical stage of your work you are working for a company that has, or is regulated under a quality management system which is derived from AS9000. For maintenance staff and pilots the requirement to have any flight control work inspected by at least one other person (two in many countries) who were not physically involved in the original maintenance is just one small example of where AS9000 is reflected in your work.
See
AS 9000 - the Aerospace Quality Management System — Quality Management System for a brief overview.