Some custom check model functions can be created in the ruleset. It allows to add new checker easily and to increase the model checker capabilities. They will be added to Rhapsody model checker when the model is loaded.

The custom model checker rules are created with JSCheck functions. They can be added in M2MRuleSet or M2MPackage.

The implementation of the JSCheck must be updated with some javascript code. Two tags can be updated:

• metaclasses: defines on which metaclass the check will be done.
• severity: defines the severity level of the check. If the severity is defined as "error", then the transformation will not be launched if the check fails.

The java script function must return a string. If the check is OK, the returned string must be empty, in other case, it must contain an error message.