This is another post about TOGAF. Check other posts in the series.
Objectives
TOGAF divides Phase C into two, covering the development of the Data and Application Architectures. As with the B and D architecture development phases, the objectives are to develop the target information systems architecture for data and application and to identify candidate architecture roadmap components based upon the gaps between Baseline and Target Architectures.
Phase C always involves a combination of Data and Application Architecture. Providing both are covered, it doesn’t matter in which order – either can go first or even paralel, based on what suits particular scenario. The key differences between Data and Application are in the subject matter, which is reflected in the use of different reference models, techniques, and architectural representations.
The Data Architecture describes the structure of an organization’s logical and physical data assets and data management resources.
The Application Architecture provides a blueprint for the individual applications to be deployed, their interactions, and their relationships to the core business processes of the organization.
Approach
The steps for Data and Application are very similar – selecting reference models, viewpoints and tools, developing a baseline and then target architecture description, performing gap analysis and defining candidate roadmap components. After conducting a formal stakeholder review the architecture is finalized, and the Architecture Definition Document created.
Techniques
- Data modeling diagrams (example: entity-relationship diagram, class diagram, etc).
- Application modeling techniques (example: OMG’s Model-Driven Architecture (MDA)).
Inputs
As always, inputs comes from previous phases, with materials useful when developing Data and Application Architectures, like:
- Data and Application principles
- Relevant technical requirements that will apply to Phase C
- Gap analysis results (from Business Architecture)
- Re-usable building blocks (from organization’s Architecture Continuum, if available)
Outputs
The main outputs are as follows:
- Baseline Data Architecture
- Target Data Architecture
- Baseline Applications Architecture
- Target Applications Architecture
- Data Architecture views corresponding to the selected viewpoints addressing key stakeholder concerns
- Applications Architecture views corresponding to the selected viewpoints addressing key stakeholder concerns
- Data Architecture Report, summarizing what was done and the key findings
- Applications Architecture Report, summarizing what was done and the key findings
- Gap analysis results:
- Areas where the Business Architecture may need to change to cater for changes in the Data and/or Applications Architecture
- Constraints on the Technology Architecture about to be designed
- Impact Analysis (see Impact Analysis)