The requirements for documented procedures are 4.2.1 (a), (b), (c) and (d).
(c) calls for the six that are mandated, but if you only do these six you don't have a management system. To understand this, I think it helps to keep in mind that the objective of an ISO 9001-compliant QMS is to help people to work in a repeatable, predictable fashion so that products and services are of depenable, known quality.
I think it's helpful to think of (b) and (d) between them as the heart of your management system, with (c) the heart of the infrastructure that supports it, all aligned towards (a), your objectives.
For the quality manual, (b), *please* don't rewrite ISO 9001 replacing "shall" with "will", as so many do. It's quicker to say, "we will be compliant with ISO 9001" and write a real quality manual. I find it's often helpful to think of the audience for the quality manual as the customer: what do they want to know about how we do business?
For the "douments needed by the organisation" I think it's helpful to think of the audience for them as new hires: what do we want to tell someone new to the job about how we want them to work? (To answer this question I'd ask the people who do the work. I'd remind them of their first day at work, when everyone told them to do what to do and how to do it -- but they got different stories from different people, often wrong ;-) By keeping this audience firmly in mind you can also decide what to put into training materials, and what needs to be to hand as day-to-day procedures.
Keep in mind also that people are more effective when they understand the context of their work, the surrounding processes, departments, work flows. That's often best communicated with process maps, with a quality manual bringing the whole thing together with an overview of "how we do business around here."
How much detail? Well, what's useful? Here's an example: I scoffed at a company once when I saw them document the arrangement of cones for the parking lot in winter snows ... until I saw that they got two feet or more of snow in their Illinois winters, there were serious safety hazards for workers walking between one building and the next, tripping over now-hidden concrete ridges surrounding the flower beds, and the people arranging the cones (so you could avoid hidden hazards) were temporary workers. "Useful" in this context meant "avoiding insurance claims for injuries."
Of course you'll usually be more concerned with design, assembly and test procedures in a manufacturing environment, but the same principle applies: if a document tells someone something useful, it's worth having.
Hope this helps,
Patrick
