The INSPIRE requirement for QoS metadata for Spatial Data Servives

The INSPIRE Directive of European Union requires declaring the following Quality of Service metadata criteria for Spatial Data Services:

• perfomance (based on initial response time and download speed),
• capacity (number of simultaneous users served without notable decrease in performance)
• availability (successful response within the performance criteria limits at least 99% of the time for test requests sent at least 6 times an hour 24/7/365)

The new INSPIRE Technical Guidance for Metadata (version 2.0, expected to be published in autumn 2016) requires declaring these criteria for each service as part of their ISO 19139 metadata using the gmd:report/gmd:DQ_ConceptualConsistency element:

<gmd:report>
  <gmd:DQ_ConceptualConsistency>
    <gmd:nameOfMeasure>
      <gco:CharacterString>Minimum performance</gco:CharacterString>
    </gmd:nameOfMeasure>
    <gmd:measureIdentification>
      <gmd:MD_Identifier>
        <gmd:code>
          <gmx:Anchor
            xlink:href="http://inspire.ec.europa.eu/registry/metadata-codelist/
QualityOfServiceCriteriaCode/minimumPerformance">minimumPerformance</gmx:Anchor>
        </gmd:code>
      </gmd:MD_Identifier>
    </gmd:measureIdentification>
    <gmd:measureDescription>
      <gco:CharacterString>The maximum time in which a typical request to the
Spatial Data Service can be carried out in a off-peak load situation</
gco:CharacterString>
    </gmd:measureDescription>
    <gmd:result>
      <gmd:DQ_QuantitativeResult>
        <gmd:valueUnit xlink:href="http://www.opengis.net/def/uom/SI/second"/>
        <gmd:value>
          <gco:Record xmlns:xs="http://www.w3.org/2001/XMLSchema"
            xsi:type="xs:double">1.56</gco:Record>
        </gmd:value>
      </gmd:DQ_QuantitativeResult>
    </gmd:result>
  </gmd:DQ_ConceptualConsistency>
</gmd:report>

Each of the QoS criteria (performance, capacity and availability) would be declared using a separate gmd:report/gmd:DQ_ConceptualConsistency element.

While this approach certainly works, a more straight-forward alternative could be useful, especially for clients which are not able or don't want to issue a separate request for retrieving the ISO metadata records for the services in addition to the Capabilities documents.

-- IlkkaRinne - 15 Jul 2016