-- Reconsider Dependencies (lines 1331-1336 in PR1)
Analogous to the relationship between actions and preconditions, the Process Model may imply Dependencies for the indicated process to proceed. Whereas a precondition applies to individual actions whenever the action is performed, the dependencies on a process model indicate conditions that are required by the process as a whole. For example, a process that includes use of simulation resources may require a valid account against which the costs of the simulation can be billed. This may not apply to any particular action comprising the process, but constrains the process as a whole. Dependencies related to the process model do not affect the presence of a service although these may affect whether the business function successfully completes.
- Section 4.1.1.2.2 talks about Reachability, and the last paragraph (lines 1177-1181 in PR1) discusses service presence. What also needs to be noted is that presence is a prerequisite for reachability but it isn't enough -- a service may have presence but the prospective consumer loses connectivity, and so the consumer loses reachability. A ping demonstrates testing presence and reachability; an average service availability only conveys how often the service is here and not how often the consumer can get to it. I'm not sure what I want to say on this in the RA, but I think it is worth noting what should be the obvious but had previously eluded me.
Ken
------------------------------------------------------------------------------------------
Ken Laskey
MITRE Corporation, M/S H305 phone: 703-983-7934
7515 Colshire Drive fax: 703-983-1379
McLean VA 22102-7508