Requirements that handle IKIWISI, COTS, and rapid change

In the good old days, dealing with software requirements was relatively easy. Software requirements were the first order of business and took place before design, cost estimation, planning, or programming. Of course, it wasn't simple. Certain straightforward criteria required satisfaction: completeness; consistency; traceability; and testability. The recent developments of IKIWISI (I'll know it when I see it), COTS (commercial-off-the-shelf) software, and the increasingly rapid change in information technology have combined to unsettle the foundations of the old airtight requirements approach. These complicating factors are examined.