This blog entry provides some “behind the scenes” commentary concerning the creation of the documents collectively known as IT Strategies from Oracle.
There were three key concerns that the Oracle Reference Architecture (ORA) documentation approach needed to address:
- Define and document a single reference architecture
- Support incremental delivery
- Ability to add new technology strategies as they emerge
For this blog entry I’ll describe the approach and rationale for item number 1.
A key concept built into ORA is that there is a single reference architecture. The more common approach is to create multiple different reference architectures, each focused on a particular set of technologies, which creates a problem when an IT environment needs to incorporate two or more of the disparate reference architectures. Rather than creating separate reference architectures, ORA addresses “sets of technology” via perspectives (e.g. SOA perspective). Each perspective provides a view of ORA focused on a particular set of technology.
This may seem like simply semantics, but the ramifications of this approach are actually far reaching. First, following the single reference architecture approach required that all the documents follow consistent terminology, no easy feat in an industry where most terms are ill-defined and many are overloaded. [There have been hours of discussions (i.e. arguments) on what, specifically, a single term means when used in ORA.] Additionally, meta-models (maturity model, SOA Service, functional breakdown levels, etc.) were created which all of the documents follow and incorporate as appropriate. (Arriving at agreement on the meta-models took weeks or months, depending on the topic.)
In addition to terminology and meta-models, the perspectives provide a consistent set of architectural views (‘view’ as defined by IEEE 1471). However, there is little attempt to have each model (IEEE 1471) within the view follow a standard structure across perspectives. Instead, the goal of each model within the architectural view is to clearly illustrate the concepts being presented i.e. we have chosen clarity over contrived consistency.
The ITSO Overview document describes the entire structure followed by ITSO.