concrete example for joint action

[Ken Laskey <klaskey@mitre.org>]

Per action item from last telecon.  The following scenario may (should?) also provide concrete hooks for other things in ecosystem.

Scenario:

1.     1. Service Provider owns service and publishes service description to make potential Service Consumers aware of the service.  [Joint action: Service Provider and catalog where service description published]

2.     2. Service Consumer (for use of service directly, use of service as part of composition, or use of service to create composition) searches catalog for service meeting needs, e.g. target criteria to be compared against service description. [Joint action: Service Consumer and catalog]

3.     3. Service Consumer retrieves [Joint action: Service Consumer and catalog] and examines service description of likely match to target criteria and decides if appropriate for use.

a.     Does service functionality sufficiently match need?  Are real world effects that will result from service interaction desirable and/or acceptable?  What certifications are available?

b.     Are conditions of use (i.e. associated policies) acceptable?  Does Service Consumer meet any requirements stated in or referenced by service description?

c.      Is required information exchange understandable by Service Consumer, i.e. can the Service Consumer use the specified structure and semantics ?

d.     Do promised and/or collected operating metrics satisfy needs?

e.     Is service reachable at published endpoint?

4.     4. Service Consumer determines willingness to use service based on sufficiency of match to needs (in terms of 3a-d) and reachability (3e).  (Service Provider is assumed to have willingness if Service Consumer abides by specifics of service description.) Service Consumer willingness also depends on Service Consumer balance of trust that Service Provider can provide service as described under conditions as promised or measured and risk of consequences if there is some degree of failure. [Possible joint action: Service Consumer and other sources of information about service and Service Provider]

5.    5.  If Service Consumer establishes willingness to consume service (i.e. necessary conditions and alignments establish execution context), Service Consumer exchanges messages to perform action against the service. ]Joint action: Service Consumer and service]

6. If Service Consumer has not established willingness because issues remain unresolved, Service Consumer and Service Provider may identify compromises or other accommodations so both Service Consumer and Service Provider can both establish willingness. [Joint action: Service Provider and Service Consumer] 

Now, at 344 words, this may be longer than requested, but it provides hooks to hang things on.  If this is useful, an abbreviated form of the scenario could be introduced and  then specific parts elaborated as used.

Ken

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Ken Laskey

MITRE Corporation, M/S H305      phone: 703-983-7934

7515 Colshire Drive                         fax:       703-983-1379

McLean VA 22102-7508