SOA and TOGAF
SOA is a more of bottom-up model where in TOGAF is more top-down model.For the successful EA; one must understand both the model. Most of the RUP based implementation such as OOA/P are heavily influenced by top-down; If too much concentration at higher level, then every fear is that system might never built.
The TOGAF ADM phases like oppartunities and solutions, migration planning, implementation governance (E, F, and G phase) mostly inltrgh RUP.
TOGAF phases naturally fits SOA style of initiative. In Business Architecture phase one need not essentially know the what should be done with the technology. The business operations must be defined with out keeping implementation in mind.
In IT architecture phase, along with defining the new services, care must be taken to cohessively work with existing legacy applications; that will not be converted "services"
Architectural Standards
Every company should have architectural standards;reference base to reduce the structural complexity of the software system in development system.
Architectural governance means enforcing such standards into software development system to bring in modularity, consistency in the system. Lack of such governance will reduce the chances of meeting architectural decisions and vision with implementation (code).
Architectural standards/rules are: -- Layered Architecture-- Seperation of concerns-- Domain Driven Design-- DAO layer should not depend on other layers-- Presentation layer should not directly interact with DAO layer-- Service layer should never call web layer-- Service objects shoud be created using factory classes
EA issues
Following are few enterprise issues should have support from development platform:-- Scalability-- Concurrency-- Transaction-- Robustaness-- Performance-- Atomicity
EA decisions
-- Choice of tools/frameworks-- Choice of programming languages-- Choice of platform-- Choice of OS-- Choice of database-- Choice of architecture style
MDA
The Model Driven Architecture (MDA) enables business user to define the business processes using standards like UML, MOF (Meta Object Factory) and CWM (The Common Warehouse MetaModel) which seperates the business logic from application logic. Using MDA, business or underlying technlogies shall be changed to gain the advantages of new business trends or technological solutions.
MDA->UML,MOF or CWF->J2EE, .NET, WebServices etc
