Abstract: A method, apparatus, and computer instructions are disclosed for generating XSLT documents from multiple versions of a UML model or XML schemas created from multiple versions of a UML model. The innovative tool can take a newer and older version of a UML model, or the XML schemas created from a newer and older version of a UML model, and run those documents through a difference tool that produces a report describing the changes made to the older version by the newer version. Then, an XSL template-match fragment can be created for each “feature added” change made to the older version. Each such XSL template-match fragment can be used to filter the corresponding configuration settings from an XML document in the newer schema's format. Also, for each “feature added” change made to the older version, an XSL template-match fragment can be created and used to add the configuration setting(s) and a default value to an older document.