I am looking for a complete categorization businesses in general, such
as
- procurement, research and development, production, marketing, sales,
accounting, legal, fulfillment, ...
as well as their subcategories in order to build up a stable filing
system according to which all business processes should be structured.
This can become of course very elaborate, and so far I haven't even
found a rough structure anywhere. Under Marketing, for instance, there
are the market research, product marketing, public relations and so
on. For each of the above and any other I have forgotton I would like
a general scheme/system.

The business at hand is a conventional (B2C) retail business of
cosmetic products.

I could imagine that there are some white papers or academic papers
out there which discuss that subject. If those could be obtained that
would be ideal. However, the basic need is the categorization itself.

Hagen

Following is a white paper that goes deep into contents and file management.
(this is in pdf format, reader plugin may be required)
www.readware.com/materials/ Readware_Understanding_Content.pdf 
following is an excellent whitepaper explaining the categorization 
techniques and technologies.
www.inxight.com/pdfs/white_papers/ cat_tech_new_ling.pdf

If you want a solution to manage your files effectively:
Depending on your requirments & budget there are many such solutions 
available in the market. I myself have been working with a company for a while
on such a system. It provides solutions for small to medium sized companies.
You may visit the company website on
www.softwaresoft.com
inquire on their products, you may customise your requirments there.
Another company Semio, has been dealing in the same solutions for medium
to large companies.
Knowledge management software vendor Semio last week unveiled the 
latest version of its content categorization and indexing engine 
designed to help customers better handle the thousands of digital 
documents they are dealing with these days....read more
source (http://www.nwfusion.com/news/2002/132088_04-29-2002.html)

Thanks for these variuos links to file content management solutions.
They are clearly helpful for one aspect of my original question.
However, for the moment I just need a rather static categorization of
all the business processes in a company such that I can file the
physical invoices, receipies, catalogues, proposals, contracts,
correspondence with business partners, customers and so on. I simply
noticed that this is growing out of hand and now I have several
similar categories or folder systems as physical folders, folders in
my computers, the email folders in the outlook and the folders for
favorites. Those I want to unify such that I and my partners know
where to find things much easier than having to cope with a couple of
slightly different filing hierarchies/systems.

The systems mentioned in your comment are basically able to
automatically assign a document to a certain category and then file it
there, as far as I understand. For my purposes I can rely on assigning
the category manually, because I need to reed the document anyway,
rather than a filing system for archiving purposes which stores all
the news in a database and waits there until somebody requests the
specific data item. So, basically, I would like to know what useful
categories exist, so that I can set the system up in advance and don't
have to re-shiffle the system everytime I get a new item which doesn't
find in any current category.