Introduction

The purpose of this International Standard is to define and/or design an initial set of Quality Measure Elements (QME) to be used throughout the product life cycle for the purpose of Systems and Software Quality Requirements and Evaluation (SQuaRE). The document also gives a set of rules to design a QME or verify the design of an existing QME. The content of this document constitutes the link between the ISO/IEC 9126 series of standards and the subsequent SQuaRE series of standards.

A number of QMEs for quality measures that quantify some of the characteristic and subcharacteristic represent an initial list, which is to be used during the construction of the quality measures as referenced in ISO/IEC TR 9126‑2, ISO/IEC TR 9126‑3 and ISO/IEC TR 9126‑4. Quality measures presented in the SQuaRE series (Figures 1, 2) were extracted from ISO/IEC TR 9126 series but it is not the only source. When evaluating selected quality measures, the user should first understand the definition of each property related to a QME used within the selected quality measures.

The main purposes of defining and using the Quality Measures Elements (QMEs) in this document are:

• To provide guidance for organisations developing and implementing their own QMEs;
• To promote the consistent use of specific QME for measuring and using the product properties that are relevant to different product quality characteristics and subcharacteristics;
• To help identify a set of QMEs that are uniquely required to derive all the quality measures for a given set of characteristics or a set of subcharacteristics of a product.

The QMEs are the common components of a number of quality measures. The intended usage of this International standard is that users will be able to select and define relevant valid QMEs to define internal, external, data or quality-in-use quality measures. Then, these can be used for quality requirements definition, products evaluation and quality assessment but not necessary limited to those. It is therefore recommended to use this document prior or together with the ISO/IEC 2502n series of standards.

Figure 1 — Organisation of the SQuaRE series of international standards

Figure 1 illustrates the organisation of the SQuaRE series representing families of standards, further called Divisions.

Figure 2 — Structure of the Quality Measurement Division

Figure 3 — The relationship of ISO/IEC 25021 as a link between the 9126 series and the SQuaRE series of standard

The ISO/IEC 9126 series is composed of four documents that list and describe the characteristics, subcharacteristics and quality measures that are referred to as the quality model. The SQuaRE quality models categorize product quality into characteristics which are further subdivided into subcharacteristics and quality properties (ISO/IEC 25010). Each quality measure within ISO/IEC 9126 series is composed of at least two QMEs. The properties (of a product) are linked to the QME (ISO/IEC 25020), using a measurement method. The 2502n series designs and describes quality measures and associated QMEs for all the quality (sub)characteristics in the quality model.

BS ISO/IEC 25021:2012

Systems and software engineering. Systems and software Quality Requirements and Evaluation (SQuaRE). Quality measure elements

Current

Published:

30 Nov 2012