ISO IEC TR 9126-3-2003 PDF

Full title and description

ISO/IEC TR 9126-3:2003 — Software engineering — Product quality — Part 3: Internal metrics. This technical report defines a set of internal (static) metrics to measure attributes of the software product that support the external quality characteristics defined in ISO/IEC 9126‑1. It is intended as a reference set of metrics that developers and evaluators can select, adapt or extend for product-quality measurement and evaluation.

Abstract

ISO/IEC TR 9126-3:2003 provides internal metrics for measuring subcharacteristics of the six external quality characteristics introduced in ISO/IEC 9126‑1. The report explains how to apply metrics, offers a basic set of metrics for each subcharacteristic, and includes an example of application across the software product life cycle. The metrics are presented for reference and are not an exhaustive or prescriptive set.

General information

• Status: Withdrawn (technical report withdrawn and replaced by later SQuaRE standards).
• Publication date: July 2003.
• Publisher: International Organization for Standardization / International Electrotechnical Commission (ISO/IEC), developed by ISO/IEC JTC 1/SC 7.
• ICS / categories: 35.080 (Software).
• Edition / version: Edition 2 (2003).
• Number of pages: 62 pages (official ISO bibliographic entry).

Scope

Defines internal (static) metrics that measure properties of the software product itself (for example size, complexity, modularity-related attributes and code-level indicators) which are linked to the external quality model in ISO/IEC 9126‑1. The document describes metric definitions, measurement intent, applicability and an example of applying the metrics during the software product life cycle; it does not prescribe specific threshold values or grades, leaving those to be defined per-product or per-domain.

Key topics and requirements

• Definitions of internal (static) software metrics mapped to the ISO/IEC 9126 quality model (six external characteristics and their subcharacteristics).
• A basic, non‑exhaustive set of metrics for each subcharacteristic (size, complexity, coupling/cohesion indicators, structural measures, etc.).
• Guidance on how to apply and interpret metrics during development, testing and maintenance.
• Examples illustrating metric application across stages of the software life cycle.
• Recommendation that users may select, adapt or define application‑specific metrics; the report does not assign universal pass/fail thresholds.

Typical use and users

Used by software developers, quality managers, evaluators, maintainers, suppliers, acquirers and other stakeholders who need a reference set of static/product metrics to support quality specification, measurement, evaluation and improvement activities. It is applied during development, code review, maintenance and when defining quality requirements tied to measurable product attributes.

Related standards

Part of the ISO/IEC 9126 family (ISO/IEC 9126‑1: quality model; ISO/IEC TR 9126‑2: external metrics; ISO/IEC TR 9126‑4: quality in use metrics). The 9126 TRs have since been superseded within the SQuaRE series; ISO/IEC TR 9126‑3:2003 was replaced by ISO/IEC 25023 (measurement of system and software product quality) as part of the ISO/IEC 25000 series.

Keywords

internal metrics, static metrics, software quality, product quality, ISO/IEC 9126, measurement, complexity, coupling, cohesion, SQuaRE, ISO/IEC 25023.

FAQ

Q: What is this standard?

A: ISO/IEC TR 9126‑3:2003 is a technical report that specifies a reference set of internal (static) software metrics intended to measure attributes of the software product that relate to the external quality characteristics defined in ISO/IEC 9126‑1.

Q: What does it cover?

A: It covers definitions and application guidance for internal metrics (size, structural, complexity and other static measures), mapping those metrics to the ISO/IEC 9126 quality model subcharacteristics, and provides examples of metric application across the software life cycle. It does not prescribe universal thresholds or grading rules.

Q: Who typically uses it?

A: Developers, evaluators, quality managers, maintainers, suppliers, acquirers and other stakeholders who need reference metrics for specifying and measuring software product quality.

Q: Is it current or superseded?

A: ISO/IEC TR 9126‑3:2003 has been withdrawn and superseded by the ISO/IEC 25000 (SQuaRE) series; measurement updates were incorporated into ISO/IEC 25023 (published 2016). It should be treated as legacy guidance and consulted alongside the current SQuaRE standards for up‑to‑date metric definitions and practices.

Q: Is it part of a series?

A: Yes — it belongs to the ISO/IEC 9126 series of documents on software product quality (parts 1–4). The 9126 series has been succeeded by the ISO/IEC 25000 SQuaRE family, which reorganizes and updates product‑quality measurement and evaluation.

Q: What are the key keywords?

A: Internal metrics, static measurement, software quality, product metrics, complexity, coupling, cohesion, ISO/IEC 9126, SQuaRE, ISO/IEC 25023.