Re: [soa-rm-ra] RE: Service & Capability, bis

[James Odell <email@jamesodell.com>]

Title: Re: [soa-rm-ra] RE: Service & Capability, bis

Hi again, Jeff,

In addition to aligning 4.3.2 and 3.3.1, 4.2.1 might be added in there.  Here, the notions of Capability, Service, and Need might be reconciled a bit more.

Cheers,
Jim


On 1/30/09 1:07 PM, "Estefan, Jeff A" indited:

> Hi Jim,
>  
> We never really fully defined “capability” in the RM.  Instead, we took the approach that it meant more or less the “ability to do something.”  A little vague admittedly, but certainly OK from an abstract RM perspective.
>  
> People usually associate doing something with functionality; hence, capability and functionality are often used synonymously when talking about services.  In my opinion, capability goes beyond just the ability to do something (i.e., functionality) but also how an offering (e.g., service) performs that capability; in other words, its quality attributes.  And both (functionality and quality attributes) should be part of that offering’s advertised description.  If not, how do I as a consumer decide whether or not the offering is going to meet my needs? 
>  
> The distinction between capability and real world effect was essentially taken from the perspective that the former is an a priori notion (i.e., what the service can do or is suppose to be able to do prior to invocation) and the result of invoking the service to realize the capability.  The latter we refer to, of course, as real world effect.
>  
> Clearly, a real world effect cannot occur unless there is some action or set of actions performed by an initiator (consumer) and an action or set of actions performed by the receiver (service).  This is why we introduced the concept of “joint action” in the RA.  In other words, there has to be a speaker and a listener in order for something to happen (i.e., real world effect to occur).
>  
> You do raise a good point between the two uses in 4.3.2 and 3.3.1 that we would should try and do a better job of aligning.  Neither statement is really wrong per se, it’s just that it would be better if we could be a little more clarity on the relationship between action (or joint action), capabilities, and real world effect as you’ve suggested.  Something we should take the action to resolve before the next public review draft.
>  
> Cheers…
>  
>  - Jeff