[Oslc-Automation] Parameters: need for input and output parameters?

[Michael F Fiedler]

An important point came up at the end of today's call around the zero-many
*parameter* attribute on Automation Plans, Requests and Results.  There was
sentiment that there needs to be a distinction between input parameters and
output parameters for Results, and possibly for each of the resources.
Continuing the discussion, here are some thoughts on what the usage might
be for each artifact:

Automation Plan:  The parameters are likely to all be input parameters.
Some may have default values, others may be empty.   These provide
consumers with a starting point of what parameters are required for
successful request creation.  Are there scenarios for output parameters on
the Plan?  None are occurring to me.

Automation Request:  When creating a Request, consumers provide the input
parameters for actual automation execution (or at least the subset of
parameters they have control over).   There is likely a scenario for the
service provider adding additional parameters to the request, but they
would still be input parameters.   Is there a scenario for output
parameters on the Request artifact?   Possibly as the result of processing
that the service provider does to "accept" the Request?

Automation Result:  The input parameters here would be a "final" record of
what parameters were used to run this automation and create the result.
As discussed today, there also seems to be a strong case for output
parameters on the result.  I.e., as the automation executed, certain
information, apart from the main result contributions, is generated and
needs to be captured in the result - especially for consumers of the result
such as downstream automations.     Examples might be the MD5 hash of a
binary which was the result of an automation or the filesystem location of
the primary automation result artifact.

We never reached the point of proposing it, but I think the direction was
to propose 2 sets of parameter attributes/predicates:  inputParameter and
outputParameter.   From the descriptions above, outputParameter might only
be appropriate for a subset of the artifacts, but could be included on all
for symmetry.

Comments?   We'll discuss in the next meeting, but a discussion on list
would be fine as well.

Regards,
Mike

Michael Fiedler
IBM Rational Software
fiedler at us.ibm.com
919-254-4170