Criterion and metric - Githubissues

GerhardHNL commented 3 weeks ago

Impacted sections

https://uncefact.github.io/spec-untp/docs/specification/DigitalProductPassport https://uncefact.github.io/spec-untp/docs/specification/ConformityCredential https://uncefact.github.io/spec-untp/docs/specification/DigitalFacilityRecord https://uncefact.github.io/spec-untp/docs/specification/SustainabilityVocabularyCatalog

Issue Description

In short: my recommendation is to combine criterion and metric in one entity based on characteristics and name it “Metric Characteristic”. The characteristic the can be a Type and a Value (expressed in different data types, if needed). This would fit for all existing models as it is all about getting metrics values for a particular type.

In more detail: In the BSP vocabulary you will find the entities “sustainability characteristic” and “metric characteristic”. These entities are based on “characteristic” which holds attributes as 'type' and 'value' and more. The difference between “sustainability characteristic” and “metric characteristic” is that the latter one is neutral, context free. Using an entity based on “characteristic” allows us not only to specify quantitative measurements but also express qualitative aspects (e.g. a yes/no is often used in thresholds, the same for a score (high, low) in footprints, rankings. Anyway, Metric & Criterion should be a solid pair in one entity. I realize, naming relates to the definition of something. Today, you will find names as: aspect, indicator, criterion, requirement, attribute, metric, benchmark, standard, property, feature, threshold. A metric is quantifiable, usually a number or a ratio that can be objectively measured, specific as it focuses on a particular characteristic, attribute, or aspect and comparable as it allows for comparison between different data points. While many metrics involve numerical values and units of measure, some metrics are more abstract or qualitative and do not rely on standard units.

Remember to add relevant labels.

onthebreeze commented 3 days ago

Thank you for this feedback.

One of the primary considerations when thinking about UNTP data modelling is whether the modelled thing is a uniquely identified node in a graph.

The UNTP Criterion is essentially a requirement or specification within a reference standard or regulation. For example an Australian standard for structural steel might specify a criterion such as minimum tensile strength for reinforcing bars. The criterion has a unique ID that is probably within the namespace of the reference standard or regulation. It is separate thing to any assessment of a specific product or facility against the criteria.
On the other hand, the UNTP Metric is not itself a uniquely identified thing. It is just a property of an assessment - eg assessment of a specific steel product against the Australian standard has a measured value that is held in the metric property of the assessment.

So I think it's not right to merge these two. Because one is a reference standard requirement (criterion) and the other is a property of an assessment against the standard.

Maybe there are better names for these things that might be less confusing - happy to hear suggestions on that - but I dont think they can be merged.

GerhardHNL commented 3 days ago

Hi Steve,

Indeed, a criterion and a metric cannot be merged into one entity. However,

a metric should refer to the attribute it relies on or measures.
a criterion (requirement) is an aspect related to a standard or regulation (often seen as (threshold) metrics.
an assessment specifies measured outcomes (measured metrics)
a measured metric is not necessarily the result of a requirement specified in a standard or regulation.
a metric always quantifies or tracks a specific aspect, characteristic, or attribute of an object, process, or system.

All could be merged?

Metric Characteristic : e.g. uri id: 12346…., type = “strength of steel” , value = 1.2 MPa, value uri id = “V12569…” associated to referenced standard “Construction Steel”

: the business name of Metric Characteristic class could be Metric, either with property measured or threshold.

Where is this construct been used?

As I remember, in an old untp conformity model ‘criterion’ and ‘metric’ were merged, but now it has been separated (see untp conformity model https://uncefact.github.io/spec-untp/docs/specification/ConformityCredential ). Anyway, now the entity ‘criterion’ is linked to assessment, but this still deviates to the BRS of product conformity https://unece.org/sites/default/files/2024-07/BRS-DigitalProductConformityCertificateExchange.pdf as a standard and/or regulation can be linked to an assessment, a standard and/or regulation holds the (threshold) metrics representing requirements, and the outcome of an assessment can be measured metric characteristics (metrics). So I do think merging is possible and something has to be fix in the untp conformity model regarding link between assessment and criterion (maybe use suggested threshold metric characteristics.

Best regards

Gerhard

From: Steven Capell @.> Sent: maandag 30 september 2024 13:31 To: uncefact/spec-untp @.> Cc: GerhardHNL @.>; Author @.> Subject: Re: [uncefact/spec-untp] Criterion and metric (Issue #155)