Think of the time that is lost just in transferring documents between word processing formats. You might use WordPerfect while your colleague uses Microsoft Word. Each program claims to read the other's format and to some extent they do. But these conversions do not work flawlessly. Time is lost reentering formatting that was lost in the conversion.
Similar problems can occur even within a single vendor's products.
SAS Institute produces proprietary file formats for its SAS datasets that must be converted using utilities to get these files from one kind of system to another. Such problems are common. Our adoption of email and the web as universal tools is a recent example of the N 2 problem. All email systems must work together if I am to be able to send messages to anyone I chose. All web browsers must agree on how to display web pages if I am to write web pages that will be readable by web surfers around the world.