From a Feb. 2009 InfoQ article by Jean-Jacques Dubray:
How can data governance complement SOA governance?
This is a key aspect of SOA governance that's often overlooked, argues Dubray.
The first step that must happen before an effective collaboration can occur: the shared usage of the Enterprise Data Model (EDM).
SOA and data governance may have very different objectives, but they share the EDM, a set of metadata Dubray defines as "a Logical Data Model, an Ontology if you will, of the overall Information System."
Dubray also argues that Message Types should be generated from EDM metadata, and the usage of traditional models like XML, ERD and UML is not suited to enable the consumption of the EDM for this purpose.
He proposes two complementary DSLs (Domain Specific Languages), one for the EDM
and one for the Message Types referencing the elements of the EDM. The DSLs are used to generate a textual notation from which EDM and Message Type definition can be captured. These DSLs are also well suited to create a graphical notation.
He concludes:
- Management of Message Types in an SOA = a complex topic
- Different approaches have been taken, but none seem to have yielded satisfactory results as they lack the backbone of an EDM
- His approach reinforces the need to start designing service interfaces from the "contract" perspective (and not the code) and establishes a reuse strategy founded on the EDM as a key enterprise asset
- Without using an EDM, service interfaces will tend to be designed with a footprint specific to projects and backend systems, reducing their ability to be reused by other consumers. The approach also enables data governance to effectively communicate changes to the EDM to the SOA governance team which will trigger a new version phase in the services lifecycles when necessary
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