Documentation/Product variants

A variant is a specialization of a product model and inherits all of is product properties, unless they are defined locally. This allows a very compact modeling of product models that vary only in a few properties.

Example: First, we define the base model for a family of laptops: foo:MacBook a gr:ProductModel, pto:Laptop ; gr:name "Macbook Pro"@en ; foo:operatingVoltage [ a gr:QuantitativeValue ; gr:hasMinValue "110"^^xsd:float ; gr:hasMaxValue "220"^^xsd:float ; gr:hasUnitOfMeasurement "VLT"^^xsd:string ] ; foo:noOfUSBPorts [ a gr:QuantitativeValue ; gr:hasValue "2"^^xsd:int ; gr:hasUnitOfMeasurement "C62"^^xsd:string ]. Then we define two variants, namely a 13 inch model: foo:MacBook13Inch a a gr:ProductModel, pto:Laptop ; gr:name "MacBook Pro 13 Inch"@en; gr:isVariantOf foo:MacBook ; foo:screenSize [ a gr:QuantitativeValue ; gr:hasValue "13"^^xsd:float ; gr:hasUnitOfMeasurement "INH"^^xsd:string ]. and a 15 inch model, which also has four instead of two USB ports: foo:MacBook15Inch a a gr:ProductModel, pto:Laptop ; gr:name "MacBook Pro 15 Inch with 4 USB Ports"@en; gr:isVariantOf foo:MacBook ; foo:screenSize [ a gr:QuantitativeValue ; gr:hasValue "15"^^xsd:float ; gr:hasUnitOfMeasurement "INH"^^xsd:string ] ; foo:noOfUSBPorts [ a gr:QuantitativeValue ; gr:hasValue "4"^^xsd:int ; gr:hasUnitOfMeasurement "C62"^^xsd:string ].

By means of the specific inference rules from

http://wiki.goodrelations-vocabulary.org/Axioms#Product_Variants

this results in the following augmented product models for the 13 inch and the 15 inch model: 13 inch model: foo:MacBook13Inch a a gr:ProductModel, pto:Laptop ; gr:name "MacBook Pro 13 Inch"@en; gr:isVariantOf foo:MacBook ; foo:operatingVoltage [ a gr:QuantitativeValue ; gr:hasMinValue "110"^^xsd:float ; gr:hasMaxValue "220"^^xsd:float ; gr:hasUnitOfMeasurement "VLT"^^xsd:string ] ; foo:noOfUSBPorts [ a gr:QuantitativeValue ; gr:hasValue "2"^^xsd:int ; gr:hasUnitOfMeasurement "C62"^^xsd:string ]. foo:screenSize [ a gr:QuantitativeValue ; gr:hasValue "13"^^xsd:float ; gr:hasUnitOfMeasurement "INH"^^xsd:string ].

15 inch model: foo:MacBook15Inch a a gr:ProductModel, pto:Laptop ; gr:name "MacBook Pro 15 Inch with 4 USB Ports"@en; gr:isVariantOf foo:MacBook ; foo:operatingVoltage [ a gr:QuantitativeValue ; gr:hasMinValue "110"^^xsd:float ; gr:hasMaxValue "220"^^xsd:float ; gr:hasUnitOfMeasurement "VLT"^^xsd:string ] ; foo:screenSize [ a gr:QuantitativeValue ; gr:hasValue "15"^^xsd:float ; gr:hasUnitOfMeasurement "INH"^^xsd:string ] ; foo:noOfUSBPorts [ a gr:QuantitativeValue ; gr:hasValue "4"^^xsd:int ; gr:hasUnitOfMeasurement "C62"^^xsd:string ]. So foo:MacBookPro13Inch inherits the operating voltage and the number of USB ports from the base model, while foo:MacBook15Inch inherits only the operating voltage but not the number of USB ports, since the latter are overridden locally.