Introduction

As information system (ICT products, software, data) and IT services are widely used, the target of their effect and influence of using them can extend from their direct users to organizations and the society. To control the effect and influence as much as possible is a social responsibility of enterprises and public/society administrations.

A wide variety of organizational functions and personal activities are increasingly performed by information systems and IT services. Therefore, high-quality information systems and IT services are essential to providing value and avoiding potential negative consequences for th stakeholders. Unfortunately, quality assurance has traditionally focused primarily on functional requirements, giving far less attention to the non-functional attributes of a system/product. Comprehensive specification, design, and evaluation of all quality attributes of information systems and IT services are critical to optimizing the value of information systems to their stakeholders.

The purpose of the "quality-in-use” model is to represent the effects and influences that can be experienced by using information system and IT service system; that is, to define, measure, evaluate and improve the quality of systems and software products and IT services when using them. Quality-in-use can be influenced by many factors including the quality of software, data and IT services.

If context of use changes, effect and influence on a stakeholder also changes.

Such context of use changes are monitored through quality evaluations of quality-in-use characteristics/sub-characteristics so that changes/gaps from initially specified context of use are identified and fed back to the next quality improvement cycle.

Full details of the changes to the quality-in-use model are in Annex A. The comprehensive specification of quality characteristics associated with a specific type of information system is represented in a quality model. A quality model can be used as an objective reference supporting requirements definition, evaluation, and validation/verification. By establishing agreed quality characteristics and their measurement, the SQuaRE family of standards provides a framework for reliable development and delivery of information systems and IT services.

This document introduces the structure of SQuaRE quality models and provides requirements for developing them. ISO/IEC 25002 describes how SQuaRE quality models in the quality model division (2501n) can be used in conjunction with other SQuaRE standards to guide quality-related activities across the information system lifecycle regardless of the development methodology. These quality models can guide the development of measures for evaluating the quality of information systems and IT services to meet the requirements of their stakeholders. These models provide a common language for describing quality characteristics that can be understood by all stakeholders. They also provide a basis for defining standard quantitative measures of quality characteristics for evaluating the quality properties of a target entity.

The complexity of information systems has grown exponentially with the advent of modern digital technologies. This complexity elevates the importance of non-functional requirements and qualities. SQuaRE quality models can help guide the development of modern digital technologies that are trustworthy and that delight their users.

Figure 1 (adapted from ISO/IEC 25000) illustrates the organization of the SQuaRE family of International Standards. Similar standards are grouped into divisions. Each division provides guidance and resources for performing a different function in ensuring system and software product quality.

Figure 1 — Organization of SQuaRE family of International Standards

The divisions within the SQuaRE family are:

— ISO/IEC 2500n - quality management division. The International Standards that form this division define all common models, terms and definitions referred to by all other International Standards from the SQuaRE family. The division also provides requirements and guidance for a supporting function that is responsible for the management of the requirements, specification and evaluation of software product quality. Practical guidance on the use of the quality models is also provided.
- — ISO/IEC 25000 : Guide to SQuaRE
- — ISO/IEC 25001 : Planning and management
- — ISO/IEC 25002 : Quality models overview and usage
— ISO/IEC 2501n - quality model division. The International Standards that form this division present detailed quality models for computer systems and software products, data, IT services and quality-in-use. This document belongs to the quality model division. This document is aligned with ISO/IEC 25002 on quality models overview and usage.
- — ISO/IEC 25010 : Product quality model
- — ISO/IEC 25011 : IT service quality models
- — ISO/IEC 25012 : Data quality model
- — ISO/IEC 25019 : Quality-in-use model
— ISO/IEC 2502n - quality measurement division. The International Standards that form this division include a quality measurement framework, mathematical definitions of quality measures, and practical guidance for their application. Examples are given of quality measures for internal and external property of product, data, IT services and quality-in-use. Quality measure elements (QME) forming foundations for quality measures for internal and external property of product are defined and presented.
— ISO/IEC 2503n - quality requirements division. The International Standards that form this division help specify quality requirements based on quality models and quality measures. These quality requirements can be used in the process of eliciting quality requirements for information systems and IT services to be developed or as input for an evaluation process.
— ISO/IEC 2504n - quality evaluation division. The International Standards that form this division provide requirements, recommendations, and guidelines for software product evaluation, whether performed by evaluators, acquirers, or developers. The guideline for documenting a measure as an evaluation module is also provided.
— ISO/IEC 25050 to ISO/IEC 25099 - SQuaRE extension division. These International Standards currently include requirements for quality of ready-to-use software product (RUSP), commercial off-the-shelf software and common industry formats for usability reports, and quality models and measures for new technologies such as cloud services and artificial intelligence.

The SQuaRE standards can be used in conjunction with ISO/IEC/IEEE 12207 and ISO/IEC/IEEE 15288, particularly the processes for the specification and evaluation of quality requirements. ISO/IEC 25030 describes how quality models can be used for systems and software quality requirements; and ISO/IEC 25040 describes how the quality models can be used for system and software quality evaluation.

The SQuaRE standards can also be used in conjunction with the ISO/IEC 33000 family of International (which are concerned with software process assessment) to provide. Standards which are concerned with software process assessment to provide:

— a framework for quality requirements in the customer-supplier process;
— support for quality review, verification and validation, as well as a framework for establishing quantitative quality characteristics;
— support for setting organizational quality goals in the management process.

The SQuaRE standards can be used in conjunction with ISO 9001 and ISO/IEC/IEEE 90003 (which are concerned with quality assurance processes) to provide:

— support for setting quality goals (and certification where applicable);
— support for design review, verification, and validation.

BS ISO/IEC 25019:2023

Systems and software engineering. Systems and software Quality Requirements and Evaluation (SQuaRE). Quality-in-use model

Current

Published:

31 Jan 2024