RE: [service-orientated-architecture] Re: What is a Service? What is an Application?

[JP Morgenthal]

It’s a very technical explanation, but it works well.  It’s definitely how I have been considering a service—a discrete unit of work.  It also works across whether a human or machine accomplishes it, which embodies the true nature of SOA.   JP   Avorcor, Inc. Integrating across the Hinges of Business   JP Morgenthal Managing Partner Avorcor, Inc. 12110 Sunset Hills Road, Suite 450 Reston, VA 20190 [EMAIL PROTECTED] tel: fax: mobile: (703) 648-1520 (703) 648-1523 (703) 554-5301   Add me to your address book... Want a signature like this?   From: service-orientated-architecture@yahoogroups.com [mailto:service-orientated-architecture@yahoogroups.com] On Behalf Of Ron Schmelzer Sent: Sunday, October 30, 2005 8:11 AM To: service-orientated-architecture@yahoogroups.com Subject: Re: [service-orientated-architecture] Re: What is a Service? What is an Application?   Here's some more fodder for thought / train of thinking to add to the discussion. Maybe a "service" is a unit of work. A Service is a unit of work that abstracts an underlying implementation using an abstract contract as a means of obligating consumers of Service functionality as well as providers of that functionality. Services expose interfaces, are described via contracts, and controlled via metadata. Service-oriented applications are composed of one or more Services and are also described via contracts, expose interfaces, and are controlled via metadata. A Service is actually an abstraction, in much the same way that an "object" is an abstraction. For those of you present in the computing space in the mid-1980s, I submit the challenges we are facing here in describing what exactly is a "Service" is the same as what we struggled in trying to define what exactly is an "object". Despite very amorphous and not very technically strict definitions of object, we still managed to grow, maintain, and justify the existence of Object-oriented architecture. I propose to you that even though the term Service may be amorphous because it describes an abstract set of capabilities that are really defined not by the what's, but by the how's (a movement away from tighly coupled. programmatic logic and towards loosely-coupled, metadata-driven declarative composition), we are still able to describe something called SOA as it compares to OO, n-tier, client/server and other forms of architecture. Just some Sunday food for thought. Ron Jan Algermissen wrote: On Oct 30, 2005, at 10:44 AM, Keith Harrison-Broninski wrote: > o I suggest that the deeper problem is that "service oriented  > architecture" is a misleading term.  A better one would be  > "distribution oriented architecture". Hmm...but what does this tell me (or imply) about the architectural  constraints and....what am I supposed to take from the idea that The "distribution oriented architecture" is a way to create  distributed software systems? Jan ________________________________________________________________________ _______________ Jan Algermissen, Consultant & Programmer                         http://jalgermissen.com Tugboat Consulting, 'Applying Web technology to enterprise IT'   http://www.tugboat.de -- _____________________________________________________________ Ronald Schmelzer [EMAIL PROTECTED] Senior Analyst ZapThink LLC Direct: 781-577-2779 / Main: 781-207-0203   YAHOO! GROUPS LINKS  Visit your group "service-orientated-architecture" on the web.   To unsubscribe from this group, send an email to: [EMAIL PROTECTED]   Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.