| Michael,
Very good. This was the point I was trying to make.
So I'd somehow like us to be clear on this in the RA, and if Michael has some particularly good examples, we may consider where they might fit in the text.
In my recent thinking, I would structure description very differently if I'm focusing on functions rather than if doing the common practice of "simple" exposing of an object via a Web Service interface. I have been advocating that if you use tools that turn objects into service artifacts, design objects to represent SOA function and don't merely turn all your implementation objects into services. No joke - I have heard people say they are SOA because they generated WSDLs from their Java objects and now have 2800 services.
My apologies to all if I confused things by sounding like I was making this the battle of OO and SOA.
Ken On Jan 23, 2008, at 4:28 AM, Poulin, Michael wrote: To the Ken's point, service is a model of a function with its features, not a object. So, the function/feature is defined first which can lead to one or many couple of data and behaviour - objects. But, it is an implementation detail. At the concept level, working with services means working with functions. This is why I always was against "simple" exposing of an object via a Web Service interface (very popular approach for service development beginners). However, similarly to an object, a service has its behaviour - business behaviour which is provided by the service body (implementation, if you want), which may be not visible via the service interface. I do have a couple of real-life examples of this. - Michael Poulin
EMF Senior Solution Architect Fidelity Investments International ' +44-173-783-6038
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@ http://www.fidelity.co.uk/ Important: Fidelity Investments International (Reg. No.1448245), Fidelity Investment Services Limited (Reg. No. 2016555), Fidelity Pensions Management (Reg. No. 2015142) and Financial Administration Services Limited (Reg. No. 1629709, a Fidelity Group company) are all registered in England and Wales, are authorised and regulated in the UK by the Financial Services Authority and have their registered offices at Oakhill House, 130 Tonbridge Road, Hildenborough, Tonbridge, Kent TN11 9DZ. Tel 01732 361144. Fidelity only gives information on products and does not give investment advice to private clients based on individual circumstances. Any comments or statements made are not necessarily those of Fidelity. The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. If you received this in error, please contact the sender and delete the material from any computer. All e-mails sent from or to Fidelity may be subject to our monitoring procedures. Direct link to Fidelity’s website - http://www.fidelity-international.com/world/index.html I'm not talking implementation (SOA can use OO principles to develop the code) but general mindset. We once agreed that asking "what is a service?" is similar to asking "what is an object?" because the answer is it could be anything that fits your problem. My thought is a service is not necessarily a good object that you operate on but more like an operation that you may be feeding objects to.
Again, this is all at the concept level, no implementation.
Ken On Jan 22, 2008, at 6:45 PM, Duane Nickull wrote: In SOA, is it necessary that there is an object behind the service? We talk to the interface (service)and don’t really care what is behind it. Assuming there is an object could be errant and architecturally un-elegant.
Duane
On 1/22/08 3:05 PM, "Ken Laskey" <klaskey@mitre.org> wrote:
Is it fair (or at least not too distorted) to say that with OO we define an object and look for what we can do to it (i.e. its methods) while with SOA we identify what we want to do (i.e. business functions) and then, if appropriate, look for objects to do it to?
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----------------------------------------------------------------------------- Ken Laskey MITRE Corporation, M/S H305 phone: 703-983-7934 7151 Colshire Drive fax: 703-983-1379 McLean VA 22102-7508
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