Thursday, October 09, 2003

Different types of dynamic "parametric variation"? In discussing Microsoft's Dynamic Systems Initiative (DSI) and its System Definition Model (SDM) with someone from Microsoft, he made the point about the importance of "dynamic configuration" (DCon). I thought about my definition of service-oriented architecture (SOA) to see if I had dealt with DC as a first class concern. It struck me that I had put "dynamic binding" (DBnd) front and center, but not DCon. So I immediately asked myself, "What's the difference between DBnd and DCon, if any?" Rather than reinvent the wheel, I went to Google to see if anyone had already answered this question. My search for "'dynamic configuration' 'dynamic binding'" returned 352 hits. I even extended my question to ask "and what's the difference between DBnd, DCon, and 'dynamic composition' (DCom), the hot concept wrapped up with SOA?" When I searched for all three terms, I got 17 hits. So my initial search leads me to believe that no one has significantly explored the relationships among binding, configuring, and composing. I can only make several basic observations about their relationships. First, all are concepts based on modularity. Second, they are all forms of what Richard Langlois refers to as "parametric variations" as opposed to "structural variations." This is an interesting choice of words, given that one sense of binding is "binding a parameter to a value." Third, binding suggests two domains being related by the binding, while configuration suggests relationships within a domain or system. In all likelihood, these terms can be arranged along a single dimension of increasing generalization, say the scope of the parameters that can be varied. Obviously, they also range across the dynamic dimension from static to real-time (e.g. binding from one wireless protocol to another without interrupting the session). 5:31:07 PM