ISO/IEC 25010:2023 — SQuaRE Product Quality Model

Introduction to ISO/IEC 25010

ISO/IEC 25010 is arguably the most widely recognized standard in the SQuaRE family. It defines the product quality model — a comprehensive framework of nine quality characteristics and their sub-characteristics that together describe what “quality” means for ICT products and software systems. The 2023 edition represents a significant evolution from the 2011 version, reflecting two decades of practical experience and the dramatic changes in the technology landscape including cloud computing, mobile platforms, AI systems, and the Internet of Things.

The product quality model applies to ICT products including software, hardware, data, and communication infrastructure. It serves multiple purposes throughout the product lifecycle: eliciting and defining requirements, validating the comprehensiveness of requirements definitions, identifying design objectives, establishing testing objectives, setting acceptance criteria for product release, and defining quality measures to support these activities. The model is designed to be used by multiple stakeholders including developers, acquirers, quality assurance staff, and independent evaluators.

The Nine Quality Characteristics

The 2023 edition organizes product quality into nine characteristics, each with its own sub-characteristics. These characteristics collectively describe all relevant aspects of ICT product quality and serve as a comprehensive checklist for requirements specification and evaluation. The table below summarizes all nine and highlights key changes from the 2011 edition.

Interaction Capability: A Modern View of Usability

The replacement of “Usability” with “Interaction Capability” marks a philosophical shift in how we think about user-facing quality. Where usability traditionally focused on ease of use for specified users in specified contexts, interaction capability encompasses a broader set of attributes including inclusivity (accommodating users of diverse ages, abilities, cultures, ethnicities, languages, and genders), self-descriptiveness (making capabilities immediately obvious without excessive interactions), and user assistance (supporting users with disabilities through multiple input/output methods such as voice, gaze, and touch). This reflects the modern reality that software must serve a globally diverse user base across an unprecedented range of devices and usage scenarios.

Relationship Between Product Quality and Quality-in-Use

ISO/IEC 25010 clarifies that product quality characteristics directly influence quality-in-use outcomes. For primary users who interact directly with the system, characteristics like functional suitability, performance efficiency, interaction capability, reliability, and security are paramount. For secondary users such as maintainers and system administrators, maintainability and flexibility take higher priority. For indirect users who receive system outputs, reliability and security are most critical. The standard provides a detailed mapping table showing which characteristics influence which stakeholder groups, enabling targeted quality improvement efforts.

Engineering Design Insights

From an engineering perspective, the 2023 revision offers several critical insights for modern software and systems engineering. The new Safety characteristic is a direct response to the growing prevalence of software in safety-critical and autonomous systems including autonomous vehicles, medical devices, and industrial control systems. Its five sub-characteristics — operational constraint, risk identification, fail safe, hazard warning, and safe integration — provide a structured vocabulary for engineers to specify and evaluate safety requirements that were previously addressed only through domain-specific standards like IEC 61508 or ISO 26262. This unification within the SQuaRE framework allows organizations to apply a consistent quality approach across all their products regardless of domain, reducing duplication of effort and improving cross-team communication about quality objectives.

The Resistance sub-characteristic under Security addresses a critical modern concern: the capability of a product to sustain operations while under attack from malicious actors. This goes beyond traditional security properties (confidentiality, integrity) to include denial-of-service resilience, ransomware protection, and the ability to maintain operations during active cyberattacks — increasingly essential for connected products and critical infrastructure.

The Scalability sub-characteristic under Flexibility acknowledges that modern systems must dynamically handle growing or shrinking workloads, a capability poorly captured by the older “Portability” concept. Combined with the new emphasis on interaction capability over mere usability, the 2023 edition of ISO/IEC 25010 provides a quality model that is far better aligned with the realities of modern ICT product development.

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