ASSEMBLY-149: Siemens comment on implementation type conformancerequirement

[Simon Nash <oasis@cjnash.com>]

I think the arguments put forward in the public review comment by
Siemens make a good case for relaxing the conformance rule that an
SCA runtime must support at least one of the OpenCSA Member Section
adopted implementation types.

The architecture of SCA has been carefully designed to support a
wide range of different technologies for implementations, interfaces,
and protocols.  The flexibility and adaptability that this provides
is a key strength of SCA, enabling the use of SCA across a very broad
range of technologies, environments and applications.

For SCA to be successful, it must be widely adopted by the industry.
Unfortunately, from this Siemens comment as well as other public review
comments, it is becoming apparent that the conformance rules in the
public review draft standard could have the effect of discouraging
broad adoption of SCA by imposing conformance requirements that are
too onerous for some prospective adopters.

The Assembly TC's response to ASSEMBLY-132 said that the requirement
to support one of the OpenCSA adopted implementation types could be
satisfied by bringing other proposed implementation types into the
OpenCSA standards.  This Siemens comment gives good reasons why this
many not be possible if the underlying implementation technology
is itself proprietary, domain specific, or non-standard.

To promote broad industry adoption of SCA, the flexibility and
modularity of the technical architecture should be matched by similar
flexibility and modularity in the conformance rules.  From a technical
standpoint there is no requirement for different components within an
SCA assembly to share the same implementation technology, as long as
each implementation technology conforms to the Assembly and Policy
specifications and passes the Assembly and Policy conformance tests.
The same requirement should be sufficient for SCA conformance.

   Simon