Enterprise Architecture (EA) is a discipline which has evolved to structure the business and its alignment with the IT systems. The Zachman Framework is an enterprise ontology and is a fundamental structure for Enterprise Architecture which provides a way of viewing an enterprise and its information systems from different perspectives, and showing how the components of the enterprise are related.
Enterprise Architecture is the process used by a business to make explicit representations of enterprise operations and resources, rather than relying on implicit notions or understanding in individual managers' heads. Stan Locke
Why Zachman Framework?
In today's complex business environments, many large organizations have great difficulty responding to changes. Part of this difficulty is due to a lack of internal understanding of the complex structure and components in different areas of the organization, where legacy information about the business is locked away in the minds of specific employees or business units, without being made explicit.
The Zachman framework provides a means of classifying an organization's architecture. It is a proactive business tool, which can be used to model an organization's existing functions, elements and processes - and help manage business change. The framework draws on Zachman's experience of how change is managed in complex products such as airplanes and buildings.
Zachman Framework vs Traditional Software Process
Many software methodologies are organized around the phases of the system development life cycle and the steps within each of these phases required to develop systems. This is expressed as consisting of: Strategy, Analysis, Design, Construction, Transition and Testing. In 1987, John Zachman published a different approach to the elements of system development. Instead of representing the process as a series of steps, he organized it around the points of view taken by the various players, providing organizations with an effective way of assessing the completeness of software development process models, in terms of an organization's information needs.
Structure of Zachman Framework
Zachman Framework is a two dimensional classification scheme for descriptive representations of an Enterprise that is structured as a matrix containing 36 cells, each of them focusing on one dimension or perspective of the enterprise. Rows are often presented as different viewpoints involved in the systems development process, while columns represent different perspectives of the stakeholders involved in the organization.
The rows of Zachman Framework focus on describing the enterprise from six viewpoint perspectives of the stakeholders. These six perspectives are based on English language interrogatives 'what', 'where', 'who', 'when', 'why', and 'how' (known as W5H).
The columns of the framework consist of a set of artifacts which are description of the enterprise from specific viewpoint of a group of stakeholders. The stakeholders are generally grouped as planners, owners, designers (architects), implementers, sub-constructors, users, or sometimes represented as viewpoints: scope context, business concepts, system logic, technology, physics, component assembles and operations classes.
The framework enables complex subjects to be distilled into systematic categories in the column headers, using these six basic questions (known as 5WH). The answers to these questions will differ, depending on the perspective or audience (represented in the rows).
Each view is a description from a particular perspective and has a representation (a model or functioning system), as indicated in the Table above. Here is a brief description of each view and model/functioning system:
Columns of Zachman Framework
The columns represent the interrogatives or questions that are asked of the enterprise. These are:
- What (data) - what is the business data, information or objects?
- How (function) - how does the business work, i.e., what are the business' processes?
- Where (network) - where are the businesses operations?
- Who (people) - who are the people that run the business, what are the business units and their hierarchy?
- When (time) - when are the business processes performed, i.e., what are the business schedules and workflows?
- Why (motivation) - why is the solution the one chosen? How was that derived from? What motivates the performance of certain activities?
Rows of Zachman Framework
Each row represents a distinct view of the organisation, from the perspective of different stakeholders. These are ordered in a desired priority sequence. A row is allocated to each of the following stakeholders:
- Planner's View (Scope Contexts) - This view describes the business purpose and strategy, which defines the playing field for the other views. It serves as the context within which the other views will be derived and managed.
- Owner's View (Business Concepts) - This is a description of the organization within which the information system must function. Analyzing this view reveals which parts of the enterprise can be automated.
- Designer's View (System Logic) - This view outlines how the system will satisfy the organization's information needs. The representation is free from solution specific aspects or production specific constraints.
- Implementer's View (Technology Physics) - This is a representation of how the system will be implemented. It makes specific solutions and technologies apparent and addresses production constraints.
- Sub-Constructor's View (Component Assembles) - These representations illustrate the implementation-specific details of certain system elements: parts that need further clarification before production can begin. This view is less architecturally significant than the others because it is more concerned with a part of the system than with the whole.
- User's View (Operations Classes) - This is a view of the functioning system in its operational environment.
Rules of Zachman Framework
The framework offers a set of descriptive representations or models relevant for describing an enterprise.
- Each cell in the Zachman Framework must be aligned with the cells immediately above and below it.
- All the cells in each row also must be aligned with each other.
- Each cell is unique.
- Combining the cells in one row forms a complete description of the enterprise from that view.
Integrating UML, BPMN, ERD with Zachman Framework
The Zachman Framework is an ontology which helps to create the structure rather than a methodology which provides the transforming process. In practice, Zachman Framework is quite popular, since it can be applied with other frameworks that emphasize the process.
The Zachman Framework can provide guidance on what kind of artifacts are needed in different stage of the process. The combined application can produce predictable and repeatable results according to the basic structure provided by Zachman Framework. The following figures show the ontology structure of Zachman Framework and combined use of the UML, BPMN, ERD and other diagrams.