The main purpose of a quality management system (QMS) is consistently meeting customer requirements and enhancing their satisfaction. The process approach is one of the eight quality management principles upon which ISO 9001:2015 is based. According to this principle, a desired result is achieved more efficiently when activities and related resources are managed as a process. So, ISO 9001:2015 invites organizations to see themselves as a system of interacting processes. One can say that the QMS is that collection of processes.
I like to use the process approach as a way of modeling how an organization works. For example, the main processes for a service providing organization can be around something like:
If your organization has other relevant interested parties you can add other processes for those other interactions
All organizations are different, so there is no universal set of processes. Each organization should design the set of interrelated processes that bests suits the purpose.
Once designed the model of how your organization works it is easy to relate each process to ISO 9001:2015 clauses. For example: the process above “Schedule the service” is mainly about clauses 8.2 and 8.5.1; the process “Purchase material or service” is about clause 8.4 and the process “Report the service” could be about clause 8.6 or 9.1.2.
Once designed the model of how your organization works it is easier to start planning the implementation.