Off hand, I don’t think there are as many as 8 to 12 that we would need to consider, at least I hope not. The service in the SOA-RM says
"While service-orientation may be a popular concept found in a broad variety of applications, this reference model focuses on the field of software architecture. The concepts and relationships described may apply to other ‘service' environments; however, this specification makes no attempt to completely account for use outside of the software domain.”
It is clearly meant to be the IT.
By the time we got to the RAF, we developed the idea of the SOA Ecosystem: Figure 2 is the SOA Ecosystem Model having the SOA-based System on the IT side and the Social Structure bringing in the idea of business as the other side of the coin. In the Kinds of Services slide, the access mechanism is the IT side, and the business idea is identified as the combination of the access mechanism and the capability it accesses. I have on numerous occasions referred to the access mechanism as the "SOA service” because it is the one explicitly focused on in the RM. I will freely admit that most things discussed in the RM have to do with the combination of the IT and capability (which may have non-IT parts) functioning in the real world.
Yes, we dropped the idea of atomic vs. composite service because opacity says the consumer doesn’t know or care and the provider can be doing all sorts of things of which the consumer should be unaware. We dropped other distinctions too because they didn’t hold up under inspection.
I just looked at section 3.1 of the RAF (the text before Figure 2) and I’ll stand by that. It isn’t perfect but it does a darn good job capturing the necessary ideas. Kudos to Frank for bring it up and sticking with it and Peter and Chris for focusing it to the essentials.
So I bring up the term(s) (Enterprise) Shared Services because it seems to proliferate with no more definition than “service” when we attacked it for the RM. I do not define the names but I would like to give them meaning.
I look at “shared service” and I ask how can a service in the ecosystem be otherwise. If I have nothing more than a single service used by a single consumer, I don’t think I’m interested. So if I explicitly focus on the sharing, what aspects must I consider. Which of these are already in the RAF and which are missing but important enough that we should discuss them now?
“Enterprise” usually enters the picture when the use of a service is so widespread and the function provided by the service is seen to be so essential that it gets an extra level of attention. What attention does it merit and by whom?
I’ll leave it at that right now.
Ken
------------------------------------------------------------------------------
Dr. Kenneth Laskey
MITRE Corporation, M/S F510 phone: 703-983-7934
7515 Colshire Drive fax: 703-983-1379
McLean VA 22102-7508
I'm also interested in discussing the topic of "shared services" (though think it is trivial from specification/ontology perspectives).
However, I am am afraid to open a can of worms that the spectrum of sensless but sound names (set around word 'service') are moving around (8 to 12 as Bob counted) .
We discussed some of them before, like 'Application Service', and concluded that an application even with a Web Service interface is not a service, and so on. Have we forgotten those discusstions and have to repeat them? [ “composite service” - I have published re-defined/updated Principles of Service Orientation based on RAF and RM and eliminated a priniciple that allowed one service to be composed by other services as contradicting other SO principles. Also, a “managed service” - which service should not managed? ]
In my recent practice, I led an establishment of shared business services in on of the major UK banks. I can share the lessons learnt if your are interested.
Regards,
- Michael Poulin
All,
The terms “shared services” or “enterprise shared services” often turn up in my world but the concepts are typically ill-defined, the criteria are nonexistent, and the ramifications have not been explored. Would this group be interested in adding this as another topic of discussion (and possibly a future document) along side our current SOA ontology work?
Note: a reasonable question is what do I mean by these terms, but I’d like to establish interest rather than just generating spam.
Thanks,
Ken
------------------------------------------------------------------------------
Dr. Kenneth Laskey
MITRE Corporation, M/S F510 phone: 703-983-7934
7515 Colshire Drive fax: 703-983-1379
McLean VA 22102-7508