Gary, (01)
I agree that being repeatable is a desirable property, but the word
"repeatable" is highly ambiguous and misleading. Do you want to
repeat exactly the same service on exactly the same data? Or do
want to do something similar with some other data? If the latter,
how would you define 'similar'? (02)
GBC> ... my models might focus on a repeatable (business) activity
> where implementations based on service models might have some
> practical payoff. So it need not be repeatable in theory, but
> in practice this is where I'm likely to focus my efforts. (03)
I think that what you want is a *type of service* that can have
an open-ended number of different instantiations for different
clients with different data at different times. (04)
In that case, I suggest that the word 'repeatable' be eliminated
by talking about types of service that can be instantiated as
needed. That implies that we need an ontology (or at least a
type hierarchy) of services. That hierarchy should have one
branch for SOA kinds of services and other branches for other
common uses of the word 'service'. (05)
I always recommend that anybody who wants to define anything
should look at a good dictionary. That doesn't mean one should
adopt those definitions unchanged, but those definitions are
written by professional lexicographers who have analyzed a
large corpus of citations. Even if they are not experts in
SOA, they know how the words are commonly used. (06)
For example, the first dictionary I picked up (MW 9th) gives
the following as definition 4b: (07)
"useful labor that does not produce a tangible commodity" (08)
This would apply to the services by a waiter in a restaurant,
a nurse in a hospital, or what most SOA systems do. But the
word 'labor' would have to be stretched metaphorically before
it could be applied to computer systems. (09)
Longman's definition 1 is (010)
"work or duty done for someone" (011)
That is followed by the following three examples: (012)
"spent a life in service to others" (013)
"died in the service of his country" (014)
"This old coat has seen a lot of service." (015)
There are more examples in these and other dictionaries, but
the general ideas can be summarized in the following points: (016)
1. Service is some kind of process or activity, which may
be considered work or labor or just some more passive
use or state, such as a coat's state of being worn. (017)
2. The server has a job, duty, or obligation to perform it. (018)
3. It is done for the benefit of someone else. (019)
4. It doesn't produce a physical product, but it may modify
or move physical entities or data. (020)
These general points can be specialized in many different
ways for different *types* of service by people, animals,
computer systems, or even coats. (021)
John Sowa (022)
_________________________________________________________________
Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/
Subscribe/Config: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/
Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx
Shared Files: http://ontolog.cim3.net/file/
Community Wiki: http://ontolog.cim3.net/wiki/
To Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx (023)
|