Yes, Perform credit check is a precondition (not even a process)
Steve 2008/10/7 Ashley at Metamaxim <[EMAIL PROTECTED]>: > Dear All > > I would like to try and sharpen my understanding of the distinction > between SOA and POA, if only because some of discussion on this seems to > be somewhat too metaphysical for my taste. > > I take it that everyone will agree that any business has some ordering > constraints on its activities that are necessary for its operations. For > instance, a Bank must "perform a credit check" before it "authorises a > loan" (although, perhaps, some Banks have thrown this one out of > late!!). Where there is a necessary constraint on the ordering of > activities such as this, there is *necessary process*. > > In any real business though, there is also *contingent process*. This > means an ordering of activities that reflects an arbitrary decision > about practice, but has no business necessity. For instance, when I get > in my car, I always "fasten my seatbelt" before I "start the engine". I > could equally well do these the other way round. > > This leads to two possible interpretations of "SOA vs. POA": > > 1. The SOA view of the business is one that abstracts away the process > view (both *necessary* and *contingent* process). This means that it is > simply a *view* of the business and says nothing about the way the > business itself (or its IT) is organised. The POA view, on the other > hand, is one that focuses on the processes. > > 2. An SOA business is one that eliminates, as far as it can, all > *contingent* process constraints from the way it conducts its > activities, leaving only the *necessary* constraints. This leads to a > minimum of "process" in the way the business defines and conducts its > activities. A POA business, on the other hand, makes no such elimination > and is therefore much more rigid. > > The first definition is just about views or abstractions; whereas the > second is a "real" distinction in the way a business defines, implements > and conducts its activities. In particular, the elimination of > "contingent process" will tend to disentangle activities from their > contingent process contexts so that they become "services". > > I take it that when people advocate "SOA over POA", they are using the > second definition. Is this correct? > > Are there other definitions of the SOA vs. POA distinction, different > from the two that I have tried to articulate above? > > Rgds > Ashley > >
