Question

Where do you draw the line between functional requirements and aspects of design?

If i can illustrate, one function of my system is that it must implement a user hierarchy.

In this instance would the definition of what those hierarchies are come under requirements (assuming you already know what the user hierarchies are) or would they come under the design aspect of a project?

Answer 1

Where do you draw the line between functional requirements and aspects of design?

Requirements is what the code needs to do. Design gets into how it will do it, with class hierarchies, design patterns used, etc.

Requirements:

There must be A, B, and C types of
user. Type A is only able to edit
their own account, type B can edit
their own account and post to hidden
forums, type C can edit all accounts
and post to all forums. The application must have a small memory footprint because blah blah blah….

Design:

Each instance of the user class will
contain a member variable of a
permissions object. The permissions
object is a wrapper for a bit field
because memory is tight, but has
several convenience methods, called
foo, bar, and baz. foo does XXX and is
public, (eventually design gets very low level and is turned
into code).

I’m not saying that would be the actual design, but that’s how the design should analyze the requirements and eventually become a working implementation.