Greetings, Readers! I would like to respond to a reader inquiry on my “About” page to give it the space it deserves.
Patty writes:

This is actually a question. Am working on a software project (I’m the tech writer). The stand-alone application is soon to be a total solution — with three add-on software modules. A customer might purchase the “original” and then one of the add-ons, or they might purchase the “original” and then two of the add-ons. The question is how to develop the docs. One of the product managers is pushing this idea (not a good one). Have the original doc, then the original doc and info for the first add-on, then the original doc and info the the first and the second add-on, etc. (you get the idea). A bad idea. Lots of duplication of information. I’m at a Friday/hard week burnout. Thoughts would be appreciated. Thanx!

First, thank you for your inquiry. I’m happy to help.

Now, to your situation. I’m tempted to ask if this is an electronic or paper document. However, your situation could be handled in a similar fashion regardless of its format. I think the easiest thing to do is to write a master document for your primary product. You can include a sentence, paragraph, or page describing the specific functions performed by your add-on module(s). This is an excellent marketing opportunity, as you can throw in some language in your stand-alone paragraph encouraging your customer/user to acquire the relevant module.

If your document is electronic and the user has obtained the side modules, you could hyperlink your master document to the new material. If your document is in paper format, you could suggest something like, “refer to the manual for Product X for further information.” In any case, your documents should each stand alone as much as possible with, at most, a reference to other documents.

Hope this helps!