Understanding Versioning

Web services as an integration architecture allow for the coexistence of multiple "versions" of each service; these versions are not cumulative or additive, but rather are variants. As such, they might reflect changing capability or data model differences, but each version can continue to operate independently and subsequent versions of a service do not supersede previous versions.

SAIP delivers several versions of its web services, labeled 1.0, 1.5, 2.0-2011, and 2.0-2012r1. These versions reflect modified capability both on the SAIP (provider) side as well as on the consumer side; some partner solutions originally built to interoperate with an SAIP 1.0 service, for example, may not have made (nor may ever make) modifications to interoperate with SAIP 1.5 or 2.0 services. This distinction is important in that it allows for a looser coupling, removing the need for providers and consumers to uptake and coordinate the release of changes. For example, one side of the integration can make changes as needed, and release those changes as a new service version; the other side can continue to interoperate using the previous service version, and if or when they decide to uptake corresponding capability, they can release their new service version, and the two sides simply flip to the use of the new service version.

SAIP provides several functional areas where a basic understanding of versioning is important, specifically in defining and setting up targets.