300 ◾ COSMIC Function Points: Theory and Advanced Practices
© 2011 by Taylor & Francis Group, LLC
ISO standard is the fact that the functional user requirements (FURs) represent “user
practices and procedures that the software must perform to full the user’s needs.
ey exclude quality requirements and any technical requirements” (Desharnais
2004, p. 19).
e functional size measurement (FSM) methods based on FURs can be used
at any phase of the software life cycle. At the end of the development phase, for
example, FSM results can be used to derive productivity ratios and to develop
estimation models. When used in the beginning of the life cycle phase, at the
requirements phase, for example, the measurement results can