Global data types (GDTs) are SAP-wide normed and reconciled data types with business-related content as they occur in standards or would correspondingly be defined there.
By them harmonization of the hierarchical signature structures of operations and the structure of the business object nodes is achieved.
The basic idea of uniform typing and hence harmonization is expressed by the following key sentence:
„ ... the same subject matter is always described (typed) by the same data type ..." (uniform typing)
Global data types represent a business-related subject matter that is described by a specified structure. If this semantic subject matter occurs in a business object node or in a B2B- or A2A operation, it is always typed by the same global data type.
This leads to uniform typing across all business objects, interfaces, and operations.
Global data types are, with regard to a subject matter, maximally defined data types that contain all elements required for the subject matter in different contexts.
GDTs can be provided context-specifically and when used in operations (or business objects) with more semantics with regard to a business-related context ("Context Data Types"). The elements used can also be restricted and integrity constraints made stricter. Thus, based on a maximal GDT further data types can be projected as context-specific restrictions.
Global data types can be defined as follows:
Global Data Types (GDTs)
... are reusable semantic building blocks for service operations and business objects
... are based on the rules described in the international standard UN/CEFACT CCTS (Core Component Technical Specification)
... have been approved SAP-wide by the Governance Process for Business Content (embedded in the SAP standard 'Application Integration & Interfaces')
... have been defined in the ESI Repository and are described by XML schema
... have been documented in accordance with the documentation templates