  Pre-Requirement Specification traceability is the activity of capturing
relations between requirements and their sources, in particular user needs.
Requirements are formal technical specifications in the solution space; needs
are natural language expressions codifying user expectations in the problem
space. Current traceability techniques are challenged by the complexity gap
that results from the disparity between the spaces, and thereby, often neglect
traceability to and from requirements. We identify the existence of an
intermediary region -- the transition space -- which structures the progression
from needs to requirements. More specifically, our approach to developing
change-tolerant systems, termed Capabilities Engineering, identifies highly
cohesive, minimally coupled, optimized functional abstractions called
Capabilities in the transition space. These Capabilities link the problem and
solution spaces through directives (entities derived from user needs).
Directives connect the problem and transition spaces; Capabilities link the
transition and solution spaces. Furthermore, the process of Capabilities
Engineering addresses specific traceability challenges. It supports the
evolution of traces, provides semantic and structural information about
dependencies, incorporates human factors, generates traceability relations with
negligible overhead, and thereby, fosters pre-Requirement Specification
traceability.
