Overview
ISO/IEC TR 14143-5:2004 - "Information technology - Software measurement - Functional size measurement - Part 5: Determination of functional domains for use with functional size measurement" provides guidance for defining and using Functional Domains when applying functional size measurement (FSM). It explains how Functional User Requirements (FUR) characteristics can be used to classify software into domains relevant to FSM, and supplies two informative example methods (Annex A: CHAR method; Annex B: BFC-type method). This Technical Report supports consistent, repeatable assessment of whether an FSM method is applicable to particular software requirements.
Key topics and requirements
- Definition of Functional Domain: A class of software based on FUR characteristics relevant to measuring functional size (per ISO/IEC 14143-1:1998).
- Characteristics of FUR: Distinctive properties of requirements that are independent of development methods, technical or quality constraints, and that are exhibited by the FUR.
- Functional Domain requirements:
- Domains must be distinct and described using characteristics pertinent to functional size.
- Domain names should use recognized IT terms (with local extensions if needed).
- FDC (Functional Domain Categorization) methods:
- Must be repeatable, consistent and structured.
- Should produce stable, well-defined domain descriptions.
- Two example FDC methods are given in Annex A (CHAR - top-down) and Annex B (BFC-type - bottom-up).
- Procedures:
- Determining the Functional Domain for a set of FUR: identify FUR characteristics, match them to reference domains, and determine applicable domain(s).
- Determining FSM-method applicability: compare domain characteristics against what an FSM Method recognizes; classify applicability as applicable, partially applicable, or not applicable.
Applications and who uses it
- Software measurement specialists and FSM method owners/designers use ISO/IEC TR 14143-5:2004 to:
- Define the Functional Domains an FSM method supports.
- Validate applicability of a chosen FSM method to a project’s requirements.
- Project managers, estimators, procurement officers and quality assurance professionals use the standard to:
- Ensure consistent functional size measurement across projects.
- Compare FUR from different sources and justify method choice for estimation, contracting, or benchmarking.
- Tool vendors and method developers can adopt FDC methods to document domain coverage clearly for end users.
Related standards
- ISO/IEC 14143-1:1998 - Definition of concepts for functional size measurement (normative reference).
- Other parts of the ISO/IEC 14143 series (Parts 1–4 and related Technical Reports) provide verification, conformity evaluation and reference models for FSM.
Keywords: ISO/IEC TR 14143-5:2004, functional size measurement, Functional Domains, Functional User Requirements, FSM Method, FDC method, software measurement.