Capability vs Function

RM Colleagues,

I noticed that we use the terms “capability” and “function” throughout the RM and in the various proposed updated definitions of SOA service but we are not clear on the distinction between the two. One of the most succinct definitions I’ve seen for capability is something along the lines of “A capability is an ability to do something based on expertise and capacity.” This would imply that a capability is measureable and I believe that to be true.

I have yet to find a satisfactory definition of a function but perhaps in this context we could argued that a function represents (the non-physics meaning of) a “unit of work” and that the plural functions would represent the performance of multiple units of work. The challenge will be to distinguish this from related concepts such as “activity” or “action.” Open to other interpretations but we need at least some notional interpretation of what we mean by function.

Either way, the two concepts of capability and function are related but are not synonymous. Perhaps we could be a little more precise in our definition of capability and consider the following:

“A capability is the ability to perform a function or set of functions based on expertise and capacity.”

<SIDEBAR>This is intended to be a separate but related e-mail thread intended to try and get us all on to a common level of understanding on these related concepts as they are fundamental to the general definition of service that we’ve been discussing in a separate thread.</SIDEBAR>

Cheers!

- Jeff

soa-rm message