Clause 3.2: Product quality terms
The product quality terms define the characteristics the model adds or changes: user controllability, functional adaptability, functional correctness, intervenability and robustness.
What clause 3.2 is
The product quality terms define the characteristics the model adds or changes: user controllability, functional adaptability, functional correctness, intervenability and robustness. The second edition adds environmental sustainability. Each definition is short and each carries a judgement about degree, which is why the requirement has to add the measure.
What the 2023 edition said
The first edition defined the five product terms and placed them in the model.
What the second edition changes
Environmental sustainability is added as a sixth product term. Functional correctness is restated against the 2023 base model.
The FDIS text is not public. The change line above is read from the public draft, which is not the FDIS and may differ. No clause level diff is invented here. The ISO stage record is the authority for the dates.
Why it matters to the buyer
The definitions are the only place where the model says what each characteristic means. A requirement that does not use the definition drifts, and a reviewer can show the drift by reading the two side by side.
What to write in the requirement
Write each requirement with the definition in front of you, then add the measure, the condition and the threshold that the definition does not supply. Keep the definition and the requirement in the same document so the link is visible.
Evidence a reviewer asks for
A reviewer will ask which definition a requirement uses. A requirement that paraphrases the definition without a measure is not evaluable.
- Requirement setOne requirement per characteristic in scope, each quoting the definition it uses and adding a measure
- TraceabilityA table linking each requirement to its characteristic and to the evidence that will show it
- Review recordThe date the definitions were checked against the edition in force
Where it commonly fails
- The requirement repeats the definition and stops
- Two requirements use the same measure for different characteristics
- The definition is from an older edition
What to do before publication
Rebuild the requirement set from the definitions rather than editing the old wording. It is faster and it removes inherited assumptions.
Read across
- 5.2 User controllability
- 5.3 Functional adaptability
- 5.4 Functional correctness
- 5.5 Robustness
- 5.7 Intervenability
- 5.8 Environmental sustainability
Source for clause 3.2: ISO/IEC 25059, Clause 3.2, retrieved 20 October 2026. The change line rests on the public draft of the second edition and ISO page 88234. The requirement, evidence and gaps are written from our record. Every source.