Technical Documents must be verified as being actually what was described as being sent to you.
This means although the document can be registered in your system, the electronic version SHOULD NOT be made available UNTIL it has been verified as being not only the correct version, but also that is readable, and not in changeable format. It may of course be marked up. 


If you have instigated an approval process, then responsibility remains with you to ensure that the you re-execute the process. It means ensuring that every (revision of every) document has a Stage or a Status.


If you have distributed this document to anyone else its is your responsibility to make sure they are on the latest revision.
Technical Documents MUST be formally issued. It is inadequate just to let people find and use what they want.


Apart from the above you must employ competent document controllers to perform these tasks. 


You MUST have documented, published, and auditable procedures. 


The following clauses of ISO9001:2008 have a direct bearing on the document control process: 4.2.3 [subclauses a,b,c,d,e,f, and g], 5.6, 6.2, 6.3, 7.1, 7.2, 7.3, 7.4.3, 7.5.1a and b, 7.5.2, 7.5.3, 7.5.4, 8.2.2, 8.3, 8.4, and 8.5.


 So it is somewhat important that the right software is used which will ensure that the  necessary processes are met in the mandated manner without further ado.

Simply put, neither Portals nor EDM Systems can meet ISO9001, whilst CEMDC software has all the necessary methodologies built in.