Designing and building solutions is often equated with software development and integration/configuration. However, any solution requires platforming, and in larger organizations the engineering of computing and network platforms capable of supporting the desired software solutions becomes a significant activity in its own right, albeit one less well covered in the popular computing press. The value chain can be seen as having both application and infrastructure tracks, with a hosting “zone of contention” in between them.
(Click to enlarge).
There is a tendency to see applications as being about development, while infrastructure is about support. This is because production support teams are often aligned with infrastructure organizations, while application support teams are aligned with development organizations. A more accurate picture is to see application and infrastructure as separate “tracks” in the value chain, with both crossing all the major value chain activities.
The hosting “zone of contention” is the continuing debate between application teams focused on functional requirements (what the application or service does) and infrastructure teams focused on non-functional requirements (how it runs). There are many variations on organizational approaches to the zone of contention; in some models the hosting team controls the technical stack up through middleware, while in other models the hosting/infrastructure team may only be responsible for the data center facility and physical access to servers, while application teams do their own operating system and middleware support. Industry trends seem to be towards re-centralization of the hosting function, as economies of scale can be had here, e.g. through the establishment of standard technology stacks as service offerings (a subject of recurring coverage in this book).
Above shows a typical progression of the application/hosting relationship. While mainframe systems usually are all the way to the right, organizations with a bias towards distributed systems may be anywhere along the spectrum. It is usually a progressive model; for example, the hosting team will not typically manage middleware unless it also controls the operating system (OS).
This table provides an overview of how the application/infrastructure tracks inter-relate through the value chain, and common issues encountered in the “zone of contention.”
(click to enlarge)
Adapted from Making Shoes for the Cobbler's Children: Architecture and Patterns Enabling IT Governance (Morgan Kaufmn, 2006).
