According to the ISO website:
The 2015 edition features important changes, which Nigel Croft, Chair of the ISO subcommittee that developed and revised the standard,
refers to as an evolutionary rather than a revolutionary process. We are just bringing ISO 9001 firmly into the 21st century. The
earlier versions of ISO 9001 were quite prescriptive, with many requirements for documented procedures and records. In the 2000 and 2008
editions, we focused more on managing processes, and less on documentation.
We have now gone a step further, and ISO 9001:2015 is even less prescriptive than its predecessor, focusing instead on performance.
We have achieved this by combining the process approach with risk-based thinking, and employing the Plan-Do-Check-Act cycle at all levels
in the organization. Knowing that today's organizations will have several management standards in place, we have designed the 2015 version
to be easily integrated with other management systems. The new version also provides a solid base for sector-quality standards (automotive,
aerospace, medical industries, etc.), and takes into account the needs of regulators.