Verify Schema Change Log for Verify Light-Duty Greenhouse Gas Updates

摘要

This document identifies XML schema modifications to the VERIFY Light Duty (LD) and Fuel Economy (FE) family of schemas to include Greenhouse Gas (GHG) data elements. There are 2 basic types of modifications. Modifications that involve internal file structure, having no impact to the logical data model, were made to bring the new schema in sync with the current schema development paradigm per EPA XML data standard (GD2-E). These changes involve only the location and organization of the schema components that comprise the logical data model and some changes to data type names. Modifications that involve the addition of new schema components to included GHG data were also made. Because the current schema development paradigm for certain kinds of data validation has moved the validation to business rules, hence making the schema much less susceptible to data requirement changes, new GHG data elements have more generic data types. Because some of the GHG data elements have been reused from the original LD schemas, these LD data elements now also have more generic data types. This basically relaxes the schema validation of the LD instances of these data elements but also requires that any business rules written for data validation for the GHG instances additionally be applied to the LD instances as well.