ISO/IEC 25010 Product Quality
ISO/IEC 25010 is the international standard that defines the product quality model: nine characteristics of a software or ICT product, each split into subcharacteristics, used to specify, measure and evaluate product quality [1]. It is the shared vocabulary most quality requirements are written in today.
1. From McCall to the 2023 model
The table shows how the top level changed since McCall.
| Model | Year | Top-level characteristics |
|---|---|---|
| McCall | 1977 | 11 factors [2] |
| ISO/IEC 9126-1 | 2001 | 6: functionality, reliability, usability, efficiency, maintainability, portability; security sits under functionality [3] |
| ISO/IEC 25010 | 2011 | 8 product characteristics, with security and compatibility at the top level, plus a quality-in-use model [4] |
| ISO/IEC 25010 | 2023 | 9 product characteristics; quality in use moved to ISO/IEC 25019 [1] |
The 2023 edition changed more than numbering [1]. It added safety as a characteristic. It renamed usability to interaction capability and portability to flexibility. It added scalability under flexibility and resistance under security, and replaced maturity with faultlessness. Many textbooks still show the 2011 model.
The next table maps McCall’s factors. McCall had no factor named security or compatibility, but their content was there, under integrity and interoperability; only safety has no counterpart at all. The same word can also mean different things in the two models.
| McCall factor (1977) | Its home in ISO/IEC 25010:2023 | Same word, different meaning? |
|---|---|---|
| Correctness | functional suitability (functional correctness) | |
| Reliability | reliability | |
| Efficiency | performance efficiency | ISO’s quality-in-use efficiency is the user’s effort, not resources |
| Integrity | security | McCall: controlled access; ISO: integrity is a security subcharacteristic, protection from unauthorised change |
| Usability | interaction capability | ISO keeps usability for quality in use, now ISO/IEC 25019 |
| Maintainability, testability, reusability | maintainability (analysability, modifiability, testability, reusability) | |
| Flexibility | maintainability (modifiability) | not ISO’s flexibility |
| Portability | flexibility (adaptability, installability) | ISO’s flexibility is McCall’s portability plus scalability |
| Interoperability | compatibility (interoperability) | |
| no counterpart | safety |
Two more false friends: suitability means functions in functional suitability, the fit of a process to the work in process quality, and a part of beneficialness in ISO/IEC 25019; self-descriptiveness is a code criterion in McCall but a property of the user interface (interaction capability) in ISO.
2. The nine characteristics
Each characteristic is a capability of a product; functional suitability, for example, is the “capability of a product to provide functions that meet stated and implied needs of intended users when it is used under specified conditions” [1].
The product quality model of ISO/IEC 25010:2023. Light green: renamed in 2023; red: new in 2023. [1]
3. Use it as a checklist
The standard’s main use is to make sure no characteristic is forgotten when requirements are written. For example, a team specifying a food-delivery app walks the nine characteristics in an hour. Functional suitability, performance efficiency, interaction capability, reliability and security all yield requirements: orders must reach the restaurant, the menu must load in 2 s on 4G, a repeat order must take at most five taps, the service must be available at lunchtime, and card data must be protected. Compatibility yields one, the payment provider’s API. Maintainability yields a target: a fix for a critical defect reaches users within 24 hours. Flexibility yields one: the app runs on the current and previous major versions of iOS and Android. Safety is dropped, and the team writes down why: the app controls nothing that can harm a person. Eight characteristics yield requirements and one is dropped, and the dropped one is as useful as the eight: a reviewer can challenge the reason. A Project Quality Model shows the resulting table.
When to use it — and when not
- Use ISO/IEC 25010 to structure non-functional requirements, test plans and evaluation reports, so that everyone uses the same word for the same property.
- Do not treat it as a specification to satisfy in full: most products need only some characteristics, and the standard itself sets no thresholds.
Limitations
The model names properties; it does not say how much of each is enough, how to measure them (that is ISO/IEC 25020 to 25029), or how they trade off. Its categories are a convention: availability sits under reliability, though many teams treat it as its own concern, and some properties, such as energy use, fit only awkwardly.
How solid is this?
- Where it comes from. The text of ISO/IEC 25010:2023, its foreword listing the changes from 2011, and the 2001 and 2011 editions [1], [4], [3].
- What is contested. Whether the decomposition is complete or orthogonal; it is agreed by committee, not derived from data.
- What we do not hold. The full 2023 text beyond the definitions of the first characteristics; the subcharacteristic names in the figure come from the published structure of the standard.
References
- ISO/IEC,“ISO/IEC 25010:2023 – Systems and Software Engineering – Systems and Software Quality Requirements and Evaluation (SQuaRE) – Product Quality Model.” International Organization for Standardization, Geneva, 2023.
- J. A. McCall, P. K. Richards, and G. F. Walters,“Factors in Software Quality. Volume I. Concepts and Definitions of Software Quality,” GENERAL ELECTRIC CO SUNNYVALE CA, Nov. 1977. Accessed: Jan. 19, 2022. [Online]. Available: https://apps.dtic.mil/sti/citations/ADA049014
- ISO/IEC,“ISO/IEC 9126-1:2001 – Software Engineering – Product Quality – Part 1: Quality Model.” International Organization for Standardization, Geneva, 2001.
- ISO/IEC,“ISO/IEC 25010:2011 – Systems and Software Quality Requirements and Evaluation (SQuaRE) – System and Software Quality Models.” International Organization for Standardization, 2011.
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