In this process, we apply the information hiding principle to the requirements specification
so that parts of the specification that are unlikely to change together are assigned to different
modules. In applying information hiding to the specification, all of the ways in which the
requirements are likely to change are identified, and the required system behavior is decomposed
into modules so that exactly one module is associated with a single change. The goal is to organize
the requirements specification so that each change requires a change to only a single module. How
this is achieved is described below.