Menu or Function Driven Software User Manuals

["Timmerman, Donald" <DTimmerman -at- ipdexch -dot- ipd -dot- anl -dot- gov>]

For the last eight years I have been documenting the operating procedures of
steam plants, water treatment plants, and high-voltage electrical
distribution systems. I have also written the same type of manuals and R&R
procedures for equipment at the other places I've worked. Here and at the
other places I've worked, I've had occasion to write and co-author several
non-commercial software user manuals.

Most of the software user manuals I've seen are usually organized in such a
way that the software is the driving force for the way the procedures are
presented (i.e., all the procedures are presented as a function of the menus
and commands). For example, the procedures are usually listed under menu and
command headings.

I have seen fewer examples of manuals that are organized in such a way that
the software functions are the driving force for the way the procedures are
presented (i.e., all the procedures are listed alphabetically by user
function). For example, procedure heading may look like the following, which
in no way resembles the software menus and commands: Create a Commodity Set,
Add Commodity Sets to an Asset Set, Create a Folder, Add Asset Sets to a
Folder, and so forth.

My question is what way do you document software for the user and why?

Don Timmerman
Argonne National Laboratory (near Chicago)