Marc said:
Any document from which you 'make engineering or other business decisions' (including mfg, etc.) has to be controlled...Any document from which you DO NOT make engineering or business decisions does NOT have to be controlled.
I like this alot. I also include in the scope of our document control procedures a statement to the effect that we only control living (revisable) documents. This stems from years ago; a PJ auditor and I "debated" the necessity to control things like a decimal/millimeter equivalent chart - no, I'm not kidding.
Vendors drop these things off all the time and they are hanging all over tool cribs and tool boxes. She argued that they were being used as a work instruction. I argued that if she followed that logic, we'd have to control calendars, machinist handbooks, my old Metrology 101 text book I keep in my office, etc. I argued that there was no need to control these things as they were fact, not revisable. She argued that they should be reviewed for accuracy (like printing errors, typos

) before they were hung out in the shop. She wrote a minor nonconformance, I did not concur and did not provide corrective action. I never heard about it again from the registrar.
I further describe a controlled document as one that is subject to ammendment action. This means I know where every copy of this document is, and if there is an ammendment, I will go get and destroy all of the obsolete copies and replace them with the current revision. I use a colored logo in the header of controlled documents. If the logo is in color, then it is an original, controlled document. If the logo is black/white, then the user knows that it is an uncontrolled copy and that he is responsible for verifying that he is using the latest revision.
For engineering drawings, we use a red "controlled if red" stamp. If the stamp is black/white, then the user knows he is using an uncontrolled copy of a drawing. We allow for this here because we only have one controlled copy in the manufacturing area and that one is attached to the router (another indication that it is the controlled copy) and our machinists often make copies of sections of drawings so they can scribble and calculate.
For documents of external origin - like Supplier Requirements Manuals provided by our customers or MSDS sheets or MIL specs - we also use the "controlled if red" stamp.