ADR Best Practices - atterdag/archflow-it-architecture-hub GitHub Wiki

ADR Best Practices

Architectural Decision Records (ADRs) are short, focused documents that capture an important architectural decision, its context, the options considered, and the consequences. They serve as a vital part of your project's architectural documentation, especially in agile environments where decisions evolve.

This page outlines best practices for creating and managing ADRs within ArchFlow and generally within your IT architecture practice.

1. What is an ADR?

An ADR records the why behind significant architectural choices. It’s not just what was decided, but why a particular decision was made, what alternatives were considered, and what consequences (good and bad) are anticipated.

Key elements of an ADR:

  • Title: Concise and descriptive, often starting with a number (e.g., "ADR-001: Choose PostgreSQL for Microservice Data Store").
  • Status: Indicates the current state (e.g., Proposed, Accepted, Superseded, Deprecated).
  • Context: Describes the forces, problem, and relevant background leading to the decision.
  • Decision: The specific architectural choice made.
  • Consequences: The positive and negative implications of the decision.
  • Alternatives Considered (Optional but Recommended): Other options evaluated and why they were rejected.

2. Why Use ADRs in ArchFlow?

  • Historical Context: Provides a living history of architectural evolution, crucial for onboarding new team members or understanding past design choices.
  • Decision Traceability: Links decisions directly to their rationale, preventing "why did we do that?" moments.
  • Knowledge Transfer: Centralizes critical architectural knowledge.
  • Accountability: Clearly states who made a decision and when.
  • Reduces Technical Debt: By documenting consequences, it encourages mindful decision-making and helps to manage anticipated debt.
  • Facilitates Discussion: Serves as a clear reference point for discussions and reviews.

In ArchFlow, ADRs are first-class citizens. They can be stored, edited, and importantly, linked to other related artifacts like C4 Models or specific Arc42 sections, creating a rich interconnected knowledge graph.

3. When to Write an ADR?

Not every decision requires an ADR. Use them for:

  • Significant Architectural Choices: Decisions that have a broad impact on the system's structure, behavior, or quality attributes (e.g., choosing a database, messaging queue, authentication method, major framework).
  • Non-trivial Trade-offs: When there are multiple valid options, and a specific one is chosen with notable pros and cons.
  • Decisions with Far-Reaching Consequences: Choices that will affect multiple teams, future development, or critical system qualities.
  • Controversial Decisions: To clearly articulate the rationale behind a debated choice.
  • Decisions that might be Revisited: Providing context makes re-evaluation easier.

When NOT to write an ADR:

  • Minor coding style choices.
  • Trivial implementation details.
  • Decisions already covered by existing standards or clear best practices.

4. Best Practices for Writing ADRs

  1. Keep it Concise: ADRs should be focused and to the point. Aim for a maximum of 1-2 pages.
  2. State the Problem Clearly (Context): Ensure the reader understands what problem the decision addresses. What forces are at play?
  3. Explain the Alternatives: Briefly describe other options considered and the key reasons for their rejection.
  4. Detail Consequences: Be explicit about both the positive and negative impacts of the chosen decision. Think about future maintenance, performance, scalability, security, cost, etc.
  5. Use Markdown: Leverage ArchFlow's Markdown editor to structure your ADR clearly with headings, lists, and code blocks where appropriate.
  6. Assign a Unique Identifier: ArchFlow helps with this, but traditionally ADRs are numbered sequentially (e.g., ADR-001, ADR-002).
  7. Maintain Status: Update the ADR's status (e.g., Proposed -> Accepted -> Superseded) as its lifecycle progresses.
  8. Link Liberally: Use ArchFlow's "Related Artifacts" feature to link your ADRs to relevant C4 diagrams, Arc42 sections, or even other ADRs. This creates invaluable traceability.
  9. Date and Author: Record who who made the decision and when.
  10. Use AI Assistant (Effectively!):
    • Start with a clear prompt describing the decision you need to document.
    • Ask the AI to generate a specific section (Context, Decision, Consequences).
    • Review, edit, and expand on the AI's output. It's a starting point, not the final word.

5. ADR Workflow in ArchFlow

  1. Identify a Decision: A significant architectural choice needs to be made.
  2. Create New ADR: In ArchFlow, navigate to your system, then "Add New ADR."
  3. Draft the ADR: Fill in the title, then use the AI Assistant and your own expertise to populate the Context, Decision, and initial Consequences. Consider alternatives.
  4. Review & Discuss: Share the ADR draft with relevant stakeholders for feedback.
  5. Finalize & Accept: Once consensus or a clear direction is established, update the ADR status to "Accepted" and save it.
  6. Link Related Artifacts: In the ADR editor, use the "Related Artifacts" selector to link to any C4 Models, Arc42 sections, or other ADRs that are affected by or provide context for this decision.
  7. Evolve: If a decision is later revised or replaced, create a new ADR (e.g., "ADR-00X: Replace Decision from ADR-00Y") and mark the old one as "Superseded," linking to the new ADR.

6. Example ADR Structure (Markdown)

# ADR-XXX: [Descriptive Title of Decision]

## Status

[Proposed | Accepted | Superseded by ADR-YYY | Deprecated]

## Context

* Describe the background, problem, forces, and challenges that led to this decision.
* What is the specific architectural dilemma or question being addressed?
* Why is this decision important now?

## Decision

* State the specific architectural choice made.
* Be clear and concise.
* Mention any key technologies, patterns, or principles involved.

## Consequences

### Positive
* List the expected benefits and advantages.
* How does this decision help achieve quality goals or solve the problem?

### Negative
* List the drawbacks, risks, or new challenges introduced.
* What compromises were made?
* Any anticipated technical debt?

## Alternatives Considered (Optional but Recommended)

* **Alternative 1:** [Brief description]
    * *Pros:*
    * *Cons:*
    * *Why rejected:*

* **Alternative 2:** [Brief description]
    * *Pros:*
    * *Cons:*
    * *Why rejected:*

## Related Artifacts

* [Link to related C4 Model (e.g., "See Container Diagram for component X")]
* [Link to Arc42 Section (e.g., "Context View section for system Y")]
* [Link to a specific Requirement]
* [Link to Superseding/Superseded ADRs]

## Date

[YYYY-MM-DD]

## Authors

[Your Name(s)]

By adhering to these best practices, your ArchFlow instance will become an invaluable, living repository of architectural knowledge, fostering clarity and informed decision-making within your teams.