What’s New > Windchill > 12.0.0.0 > End User > Options and Variants: Constraint Solver Changes for Option and Choice Rule Resolution
  
Options and Variants: Constraint Solver Changes for Option and Choice Rule Resolution
Product: Windchill
Release: 12.0.0.0
Benefit
The PTC constraint solver is introduced for resolving rules related to options and choices when applied to configurable structures through the option filter.
Additional Details
To use the PTC constraint solver, set the ato.constraint.engine.class property in the wt.properties file to com.ptc.windchill.option.choicecomponent.session.rules.engine.graph.DependencyGraphEngineSession. Set this property to specify the constraint solver used when resolving Include, Exclude, Enable, and Conditional Rules related to options and choices applied to the configurable structures.
If you do not set a value for this property, the Drools constraint solver is used by default. In a future Windchill release, the PTC constraint solver will be the default value.
The Drools constraint solver is deprecated from this release and will be terminated in a future Windchill release. PTC recommends that customers who use options and choices for configurable structures evaluate the constraint solver introduced in this release.
Related Information
For more details, see Preferences and Properties.