I've talked in the past about how IP is a spanning layer, and intermodal shipping is a spanning layer. Here's another example: flexible manufacturing. I just read a New York Times article on flexible production that describes how different types of cars can be produced on the same assembly line. The key?
Flexible assembly plants require three key attributes: programmable welding robots, standardized production practices and one-size-fits-all conveyors for the assembly line. [emphasis added] Automotive News
The last requirement dovetails with my definition of SOA (aka spanning layer), which requires the concept of generic envelope or container processing. The container becomes the fixed point, and everything else is variable:
To make this possible, Chrysler designed a flexible pallet that can convey a variety of models on the assembly line. Chrysler began standardizing production in 1998. [emphasis added] Ibid.
By designing an assembly line with the pallet as the focal point, you can more easily minimize the coupling between that pallet and what it carries. This enables adapting of the design (i.e., the network, the assembly line) itself, not just adapting the components that populate the design.
BTW, it is interesting that in the automotive industry, it is the product (automobile) that is fairly fixed, while the (production process) assembly line is becoming adaptive. Contrast that to the software industry, where the product is adaptive, while the production process is fixed.
10:34:09 AM 
