The IRD (initial requirements documents) may be a simple collection of statements.  There are two approaches to organizing these statements:

Pigeonholes:  Stick each statement into the appropriate module(s) defined in the feasibility study.  New modules may have to be created for outliers.

Agent identification:  Identify players that will interact with the system.  Define scenarios involving these players and our system.  These scenarios will be sets of tasks for each use case in the requirements representation.

Task identification can be facilitated using the IC cards