TOGAF

Architecture Principles

The Preliminary Phase

Purpose

• Enabling decision-making
  • it is important to set precedence during trade-off discussions and authority of “tie-breaking” if it must occur
• Aligning the enterprise
  • principles take subjectivity and bias out of the equation and drive critical conversations that are objective and aligned to the enterprise’s values
• Ensuring Governance
  • how will the enterprise ensure that the right decisions are surfaced at the right time and with the right decision-makers, and, moreover, how to monitor the decisions and approach taken to arrive at the decision?
• Understanding Values and culture
  • provide a better understanding about the enterprise’s culture and values; provide an approach and insight into how well the enterprise reacts to change

Template

• Name
  • Should represent the essence of the rule, and be memorable
  • Should not mention specific technology platforms
  • Should avoid ambiguous words Statement
  • Should succinctly and unambiguously communicate the fundamental rule
• Statement
  • Should succinctly and unambiguously communicate the fundamental rule
• Rationale
  • Should highlight the business benefits of adhering to the principle, using business terminology
  • Should describe the relationship to other principles
• Implications
  • Should highlight the requirements for the business and for IT for carrying out the principle
  • Should state the business impact and consequences of adopting the principle

Developing Architecture Principles

Architecture Principles are typically developed by the Enterprise Architects, in conjunction with the key stakeholders, and are approved by the Architecture Board.
Architecture Principles will be informed by principles at the enterprise level, if they exist.
Architecture Principles must be clearly traceable and clearly articulated to guide decision-making. They are chosen so as to ensure alignment of the architecture and implementation of the Target Architecture with business strategies and visions.
Specifically, the development of Architecture Principles is typically influenced by the following:

• Enterprise mission and plans: the mission, plans, and organisational infrastructure of the enterprise
• Enterprise strategic initiatives: the characteristics of the enterprise — its strengths, weaknesses, opportunities, and threats — and its current enterprise-wide initiatives (such as process improvement and quality management)
• External constraints: market factors (time-to-market imperatives, customer expectations, etc.); existing and potential legislation
• Current systems and technology: the set of information resources deployed within the enterprise, including systems documentation, equipment inventories, network configuration diagrams, policies, and procedures
• Emerging industry trends: predictions about economic, political, technical, and market factors that influence the enterprise environment

Qualities of principles:

1. Understandable: the underlying tenets can be quickly grasped and understood by individuals throughout the organisation. The intention of the principle is clear and unambiguous, so that violations, whether intentional or not, are minimised.
2. Robust: enable good quality decisions about architectures and plans to be made, and enforceable policies and standards to be created. Each principle should be sufficiently definitive and precise to support consistent decision-making in complex, potentially controversial situations.
3. Complete: every potentially important principle governing the management of information and technology for the organisation is defined - the principles cover every situation perceived.
4. Consistent: strict adherence to one principle may require a loose interpretation of another principle. The set of principles must be expressed in a way that allows a balance of interpretations.
   Principles should not be contradictory to the point where adhering to one principle would violate the spirit of another. Every word in a principle statement should be carefully chosen to allow consistent yet flexible interpretation.
5. Stable: principles should be enduring, yet able to accommodate changes.
   An amendment process should be established for adding, removing, or altering principles after they are ratified initially.