Master architecture decision records (ADRs): Best practices for effective decision-making

Architecture decision records (ADRs) help you document and communicate important process and architecture decisions in your engineering projects. Based on our experience implementing over 200 ADRs across multiple projects, we’ve developed best practices that can help you streamline your decision-making processes and improve team collaboration.

In this post, you’ll learn:

• How to implement ADRs in your organization
• Best practices based on more than 200 ADRs across multiple projects
• Practical tips for streamlining architectural decision-making
• Real-world examples from projects with 10 to more than 100 team members

Common challenges in architecture decision-making

Before implementing ADRs, your teams might face these common challenges:

1. Team alignment – Development teams spend a huge part of their time (20 –30%, based on our project experience of the past 3 years) coordinating with other teams, which can slow down feature deployment and increase costs through repeated architecture refactoring
2. Design flexibility – Finding the right balance between upfront design and evolving architecture when working with agile and DevOps approaches
3. Nonfunctional requirements – Making trade-offs between security, maintainability, and scalability requirements
4. Changing requirements – Adapting architectural decisions to evolving business goals while maintaining system integrity
5. Knowledge transfer – Onboard new team members efficiently and make sure they follow the team’s current way of working

How to streamline the decision-making process

We base the recommendations in this post on our experience with several projects, working with teams with fewer than 10 team members as well as complex projects with 100 team members across 10 work streams. We embarked on ambitious projects with a green-field start as well as projects covering ongoing development of new features in production. Especially in teams with 100 people contributing to the code base, we faced the challenge of making sure that collaboration was seamless and decision-making consistent.

To address this challenge, we implemented an ADR mechanism, which served as our guiding light throughout the project’s lifecycle. After more than 3 years of following this approach, we’ve amassed a wealth of experience and best practices that we’re excited to share with the software development community. By capturing the context, alternatives considered, and the rationale behind each decision, ADRs foster transparency, knowledge-sharing, and accountability within teams. Our goal is to guide you through the process of writing effective ADRs with the following best practice recommendations:

1. Keep ADR meetings short and focused – Effective ADR meetings should be concise and time-bound. Aim to keep them 30–45 minutes maximum. This focused approach keeps discussions on track and participants engaged throughout the process.
2. Embrace the readout meeting style – Adopt the readout meeting style, where participants spend 10–15 minutes reading the ADR document. Encourage attendees to provide written comments on sections, paragraphs, or sentences that require clarification or where they have differing opinions. This approach promotes active engagement and fosters a bias for action and frugality.
3. Maintain a cross-functional yet lean participant list – Invite representatives from each team that might be affected by the architectural decision but strive to keep the total number of participants below 10. This cross-functional representation provides diverse perspectives while maintaining a lean and efficient decision-making process, aligning with the principles of frugality and bias for action.
4. Focus on a single decision – Keep ADRs concise by focusing on a single decision. Don’t hesitate to split up decisions if necessary. Concentrating on one decision at a time simplifies the decision-making process so that participants can thoroughly evaluate the impact during readout sessions. This approach aligns with the principles of ownership and customer obsession.
5. Separate design from decision – Use a separate design document mechanism to explore alternative options thoroughly. Reference these design documents within the ADR, adhering to the principles of invention and simplification.
6. Address comments and resolve feedback – Actively follow up on comments received during the ADR review process. Resolve all comments, either by incorporating changes or by discussing and reaching a consensus with the comment author. This practice demonstrates a commitment to delivering results and fostering a sense of ownership.
7. Push for a timely decision – Avoid prolonged discussions and multiple readout meetings. Based on our experience, one to three ADR readouts should be sufficient. If more sessions are required, reevaluate the dependencies and consider reducing the number of invitees or reducing the scope of the ADR. Most of the decisions are two-way door decisions, meaning that they can be changed with little impact in the future. It’s always better to make a decision and try it fast instead of endlessly discussing it. This approach aligns with the AWS principles of working backwards, customer obsession, delivering results, and being right a lot.
8. Embrace team collaboration – Approving an ADR is a team effort. The author must own the document and gather feedback from all affected teams before finalizing the decision. This practice encourages having backbone, disagreeing and committing, and fostering a collaborative environment.
9. Maintain and follow the process – Keep ADRs up to date and follow the established process. If an ADR supersedes a previous one, document the change and link the new ADR in the superseded document. Insist on the highest standards by adhering to the defined processes—consider ADRs as a team law.
10. Centralize ADR storage – Store ADRs in a central location accessible to all project members, regardless of their team affiliation. This practice promotes transparency and makes sure that architectural decisions are readily available to everyone involved.

Implementation tips and success measures

When implementing these practices, we recommend that you start small with a pilot team, create clear templates, and establish review cycles. Defining success measures such as the time to decision, team satisfaction, architecture rework reduction, or cross-team collaboration improvement help to evaluate your decision-making process

Conclusion

By implementing these best practices for ADRs, you’ll streamline your decision-making processes, foster collaboration, and make sure that architectural decisions are well-documented, communicated, and aligned with your organization’s principles and goals. Embrace these practices and witness the positive impact they have on the success of your software projects.

Read the AWS Prescriptive Guidance for an introduction into ADRs and an example ADR or the homepage of ADR GitHub organization.

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