Introduction to visual rules modeling

Adrian Giurca, eBusiness Technologies, Craiova, March 2009

eBusiness Technologies (ebTech)

Introduction to visual rules modeling

Dr. Adrian GiurcaBrandenburg University of Technology

Cottbus, Germany


Rules in "real life"

• IF the customer is a gold customer and its current shopping cart is more than 150 EUR THEN set a 5% discount to the shopping cart.

• IF the customer is a platinum customer and its current shopping cart is more than 500 EUR THEN set a 15% discount to the shopping cart.

• All platinum customers are gold customers.


Real rules are based on vocabularies

• Classeso Customero Shopping cart

• Propertieso discounto customerName

• Q: How we discover them? • A: As in Software Engineering Design


Vocabularies (1)

• Software engineers represents vocabularies with the help of UML class diagrams

• Different constraints are expressed with OCL


Vocabularies (2)

• Semantic Web community represents vocabularies with RDFS and/or OWL

<rdf:RDF xmlns:rdf="..." xmlns:rdfs="..."><rdfs:Class rdf:ID="ex:Customer"/> <rdfs:Class rdf:ID="ex:GoldCustomer"><rdfs:subclassOf rdf:resource="ex:Customer"/></rdfs:Class><rdf:Property rdf:ID="yearSpending"><rdfs:domain rdf:resource="ex:Customer"/><rdfs:range rdf:datatype="xs:double"/></rdf:Property></rdf:RDF>


A Short Comparison

• UML provides a visual notation but a more complex XML serialization (XMI)

• RDFS/OWL provides XML syntax but no visual notation. The XML syntax is not based on XML Schema/RelaxNG therefore special validators are necessary

• UML provides support for packaging • RDFS/OWL use XML namespaces


Modeling Rules

• Q: Why to use a modeling language for rules?

• A: Simply because natural language is sometimes ambiguous and we don't know how to encode the rule

• Remember also the logic controversy...• Do you remember it?


Vocabularies and rules

Rule:If rental car is stored at the branch and rental car is not assigned to any rental and it is not a rental car scheduled for service then rental car is available at the branch.


UML-based Rule Modeling Language

• Any person being a male and is not a husband is a bachelor.

bachelor(X):- male(X), not(husband(X)).


If-Then-Else Rule

• If the order value is less than 1000 give a discount of 3% otherwise give 6%.


Derived Association Rule Example


Your knowledge on rules

• Do you know rule languages?

Drools?

• Do you use rule languages?

Drools?

• What rule-based applications you built?

Have you finished your first Drools example?

I will not work for you


Do you like rule-based applications?

Tower of Babel - Pieter Bruegel (1563)

Introduction to visual rules modeling

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