Tuesday, May 15, 2007

In Defense of Bottom Line SOA

Just when I thought I had sold the SOA community on my perspectives on the ROI of SOA, Alastair Bathgate, a fellow tech blogger whom I respect, threw down the gauntlet and took some jabs at my recent whitepaper. Two thoughts filled my head as I read his retort:
  1. He's right
  2. I'm glad he spoke up
His first point:
"Although, as Marc points out, the cost of connecting all the components in a P2P architecture is undoubtedly high, I wonder if that would ever happen in reality..."
In my paper, I based my ROI analysis on the assumption that total infrastructure connectedness is required to achieve maximum agility. However, it would be foolish to think that every last component in an IT environment would need to be connected to every other in order to produce appreciable return on integration investments. In fact, it may be altogether impossible. However, I do contend that business-critical segments of the infrastructure can be configured into fully connected integration sub-networks.

Bathgate continues:
"[Marc's] target of zero latency...is again appealing, but unlikely to be achieved...even with the most sophisticated SOA."
Again, he's right on the money. No company can ever hope to operate in absolute real-time, even with a perfectly managed service-oriented infrastructure. There are countless forces at play constantly that contribute friction to even the most streamlined business processes. (It is these forces that produce the chaos that is the theme of this blog.) In order to home in on the essence of SOA and P2P, though, I had to eliminate these variables from my equations, otherwise my analysis would have been so muddied up with extraneous data that the fundamental properties of P2P and SOA wouldn't have shined through.

Then he adds:
"...the enterprise is always dreaming up new business processes...which means that maintaining a Service Oriented Architecture can be just as painful as building P2P solutions."

"...the orchestration layer of any SOA needs constant reconfiguring to meet new business requirements."
SOA certainly can be just as painful, or more, than the P2P approach (I assume that by "painful" Mr. Bathgate means costly), but this is a function of the quality of a particular SOA implementation and is not an immutable property of SOA itself. Some SOA initiatives will succeed and some will fail. That's just the way it is, but we shouldn't fault or avoid SOA just because success is not guaranteed.

Also, I agree with Bathgate on the point that SOA is not immune to change. In fact, my ROI model is based on the assumption that service-based networks are subject to at least the same rate of change as P2P networks. The bottom line, though, is that SOA isolates an instance of change to a single location rather than allowing it to rip through the network like a shock wave.

Finaly, Bathgate closes with:
"I think that Marc has written a highly interesting and thought provoking paper that considers the “pure” arguments. He points to a fork in the road where a decision must be made to take the P2P or SOA paths. I just think that in the real world there is some dirty middle ground that we have to accept exists..."
Again, I could not agree more. My ROI model is a starting point for understanding the raw characteristics of SOA as compared to P2P. It is not meant to be construed as a methodology or formula for success. It places SOA and P2P into a vacuum, free from the influences of external, real-world forces, systematically dissects them and analyzes their DNA under a microscope. Indeed, it is a highly purified view of two extreme approaches to enterprise integration. Perhaps overly scientific for many practical purposes, but necessary to reveal their most fundamental characteristics.

Mr. Bathgate has reminded us that enterprise system integration is not a black-or-white affair. It's not all or nothing. It's not P2P or SOA. In reality, every IT organization must strike a balance between the extremes -- a blended strategy that applies the right philosophy to the right context at the right time. Use my ROI model to understand where the boundaries lie and navigate your own path to agility using sound judgment and an understanding of your business that could not possibly come from a paper you downloaded from the Internet.