The main purpose of documentation is to enable the consistent and stable operation of an organization's processes.
Although statutory, standards' or customer requirements may require certain documentation, there is no defined "catalogue", or list of processes that has to be documented in ISO 9001, apart from the 6 indicated ones.
The organization should determine which processes are to be documented on the basis of:
The size of the organization and type of its activities,
The complexity of its processes and their interactions,
The criticality of the processes and
Availability of competent personnel.
A number of different methods can be used to document processes, such as graphical representations, written instructions, checklists, flow charts, visual media, or electronic methods.