Requirements

Craig has posted a taxonomy of requirements on his blog (the taxonomy is Don Firesmith’s not Craig’s). 

I haven’t seen the discussion mentioned in the post, so I don’t know  whether it had any influence on the illustration or is independent of it.  But the nomenclature shown in the illustration, having the format of ‘X requirements’ where X can be anything from ‘Functiona'l’ requirements, ‘Documentation’ requirements, etc. got me thinking. 

A ‘requirement’ is something that someone needs from someone else.  A bit more formally, some entity needs (‘requires’) something from another entity.  When you say ‘maintenance requirements’, ou have to be clear, who is needing these requirements?

Without a clear understanding of who or what that requiree is, you can be assured that the ‘requirement’ will be muddled. 

The diagram shows ‘Documentation Requirement’ in a box.  There is an arrow from that box pointing to a box labeled ‘Product Requirements’.  What does that arrow mean?  Does it mean that documentation requirements are a subset of product requirements? And that as part of delivering the product, documentation should be delivered as well? 

If that is how to interpret the arrow, what does the arrow from ‘Business Requirements’ to ‘Product Requirements’ mean?