Introduction
Complex software systems often require an intricate network of hardware and software to process data and respond to requests. That network makes up the software’s architecture, and understanding all its interactions is challenging. So, software development teams write software architecture documentation to describe it.
Writing software architecture documentation can get difficult in itself, so developers use standardized models to keep it organized. In this article, we’ll cover a few best practices and a step-by-step process you can use to create and maintain comprehensive, accurate software architecture documentation.
What’s Software Architecture Documentation?
Software architecture documentation is a collection of resources that explains an application’s hardware and software systems. It’s a valuable source of truth that developers use to build software, onboard new developers and transfer knowledge. Without it, everyone creates their own understanding of the software’s architecture, which could be incorrect and lead to production issues.
Benefits of Software Architecture Documentation
Comprehensive documentation centralizes everything developers need to know about an application. As long as it’s maintained regularly, this resource offers the following benefits.
Enables Collaboration
Software documentation creates a shared understanding of how an application works, even at a highly technical level. When everyone has the same baseline of knowledge, they spend less time rehashing details and more time working on new projects together.
As teams update the software, they can record their design choices and rationale in one place, enabling better decision-making in the future. This also allows colleagues to revisit those choices as needs evolve. And if projects expand across departments, clear documentation establishes a shared language that enhances communication.
Makes Knowledge Exchanges Easier
Transferring knowledge from one developer to another isn’t something you can do over a quick meeting or email. There are too many aspects to cover, such as configurations, requirements and known issues, all of which involve highly technical details. Handing off a project is much easier when developers can direct each other to clear documentation.
Helps With Scalability
Comprehensive documentation captures vital information developers need as teams grow and software becomes more complex. As more team members join a project, they can reference this resource to speed up onboarding. And detailing the project's entire life cycle allows developers to make informed decisions about new features and updates.
How To Create Software Architecture Documentation: 6 Steps
Your documentation should suit the software and the team, and the following process can help you develop customized guidance.
1. Identify Your Documentation Model(s)
The two most popular models for writing software architecture documentation are the C4 model and arc42. Both frameworks provide a basic structure that keeps the documentation organized.
- Arc42 is a template for writing software documentation for different stakeholders. It starts with 12 predefined sections that you adapt for various audiences, such as technical writers, architects or developers.
- The C4 model is a technique for creating visual documentation that uses diagrams to communicate the “4 Cs”: context, containers, components and code.
Select either or both of these models as a framework for your documentation. If you choose both, use the arc42 document to describe architectural elements in detail and a C4 diagram to create a visual overview.
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2. Get a Template
Software architecture templates provide all the sections and formatting you need upfront, saving time and effort.
The arc42 template gives you 12 standardized headings, but you’ll need a preformatted document to write them into. The simplest method is to replace Scribe’s IT business plan template headings with the arc42 dozen.
For a C4 model diagram, choose a tool like Lucidchart or Figma that offers color-coded shapes, lines and labels.
3. Identify Audience and Objectives
Your software architecture documentation will look very different depending on who you’re writing it for. A technical writer, for example, will need to reference it to describe specific methods, objects or specifications to third-party developers. And a developer may require details about module interactions to effectively implement new features.
So, before drafting your resource, define your target audience and learn how they’ll use the documentation to reach their goals. Write down all the people involved in the project, and group them based on their roles. Then, ask involved parties what information they need and how it will help them complete tasks. Use this research to create your headers in your outline.
4. Collect Relevant Information
Gather all the information readers need to complete their objectives, such as specifications, source code structure and known issues. Sort this information into the headings or visuals in your template.
5. Add Context
If you’re using an arc42 document, include an introduction for each heading to provide any background information readers need. The C4 model is visual, so rearrange the diagram to provide visual cues that indicate the connections between nodes.
6. Finalize
Send your draft to members of your target audience for their feedback, and pay close attention to instances where they mention unclear or missing information. After you address these comments, publish the completed document in a shared database, such as an internal knowledge base or cloud folder.
3 Best Practices for Creating Software Architecture Documentation
The following are three helpful tips for documenting software accurately and efficiently.
1. Integrate Documentation Throughout Development
Don’t save writing the documentation for the end of each development project. Instead, make this process part of your workflow, writing necessary instructions and technical details as you create the software. That way, when the project is complete, your resource is, too.
2. Update Regularly
Whenever software is patched or updated, review your documentation to ensure it’s still accurate. Otherwise, you risk creating confusion and causing potential errors in future development. If these changes occur often, add a “Patch Notes” section to your documents so developers can learn more about what’s new.
3. Automate
Writing architectural documentation involves several repetitive tasks, such as describing every object in an API or creating installation instructions for multiple platforms. Automation tools are uniquely suited for these tasks, so take every opportunity to leverage them. Scribe, for example, can automatically generate instructions for the myriad processes your documentation needs to describe.
Using the C4 Model for Software Architecture Documentation
The C4 model uses visuals to sort elements of a software's architectural structure into four categories.
Context
The Context section illustrates how an application handles a typical use case, describing a user persona and the systems they must interact with to complete a task or solve a problem.
For example, the persona could be someone uploading their resume to a job search site. The systems involved would include their profile, the website and the web server where the file is eventually stored.
Container
The Container section focuses on how the software system transfers and stores data. It shows the flow of information from the user to the API to the database. Each node in the diagram represents a place in the system architecture where data is contained and processed. Additionally, these modules describe what happens to the data as it passes through that container.
When the user from the previous example uploads their resume, their data starts in a web server container that processes the request. It then heads to an application server, which communicates with a database container to store the resume and related metadata.
Component
The Component view zooms into each container to illustrate how it processes or stores data. It focuses on the individual elements within a container (such as a web application or microservice) and how they interact.
Say you want to explore the application server container. Within it, you'll find several components, including:
- A file handler that manages file uploads.
- A user service that retrieves user details.
- A notification service that alerts the user upon successful upload.
Each component interacts with others through defined interfaces, ensuring data flows smoothly from one part of the application to another.
Code
Your diagram's Code section highlights the source code that makes these systems work. This segment lists the methods, objects and functions that the software leverages to perform tasks.
For example, it might include an uploadFile() function that handles the resume upload process. Most integrated development environments can generate this part of the diagram for you, so it’s often left out of a finished C4 diagram to save space for the other sections.
Automate Your Documentation Process With Scribe
Creating software architecture documentation ensures everyone shares a common understanding of the software they’re working on. Writing it takes time, but by following best practices and leveraging automation tools, you can create a valuable resource for your team.
Scribe can improve your documentation process by automatically generating instructions for even the most complex tasks. Simply install the plugin or download the app and walk through the process yourself. As you work, AI captures screenshots, generates text and turns it all into an embeddable Scribe you can add to your knowledge base.
Sign up for free to discover how Scribe can streamline your documentation process.
