Fit Criterion

I thought I had completed my Requirements Analysis and Elicitation but then realised I had not added the Fit Criterion into the requirements.

Fit Criterion is the test as to whether the requirement has been successful.  It involves looking really deeply into what requirements you have written and digging really deeply into what they mean and what your customers (the system users) want.  Luckily, my parents are my customers, so I can just ring them up, day or night, and ask them what they want and how they want it to work.  However, writing all of these requirements seem to be taking FOREVER!  It didn't help that while I was writing them that I had a migraine.  That's probably why I forgot to write the Fit Criterion into the requirements to begin with.