Introduction
When starting a new software development project, you’ll quickly discover the need for a thorough software design document (SDD). It provides a high-level outline of the development team’s objectives, standards and structure. This article will describe how to write a practical design document every stakeholder can benefit from.
What’s a Software Design Document?
A software design document outlines who’s involved in development and how the platform should work.
Typically, this resource includes mockups of the finished user interface (UI) and a storyboard explaining the expected journey through the software. An SDD might also include a list of the project stakeholders and the milestones they must reach. This information helps designers make decisions that align with the final product vision.
If you’re planning a lengthy coding project, for instance, it’s essential to draft a design document before you begin. Without it, team members may have wildly different ideas about what they’re creating, which could cause confusion.
The Importance of Software Design Documents
A software design specification is essential to any development team’s strategy because it provides an overview of their goals and guidelines. With a thorough software design document in place, every stakeholder on the project can experience the following benefits.
Standardization
To ensure consistency, a great software design document includes links to style guides, recommended code structures and formatting specifications. Outlining these expectations in advance gives every stakeholder a common understanding of the project’s objectives and standards. When everyone on the team is aligned, it’s easier for them to create a cohesive final product.
Improved Communication
An SDD significantly reduces friction between team members as they discuss their approach to development. With straightforward guidelines, everyone has a single source of truth for the design goals they’re striving toward. Even if it isn’t perfect, this initial document reduces the time engineers, designers and project managers spend hashing out solutions and best practices.
Clarity
Creating a unified standard for your software design goals clarifies all the tricky elements of software development. If someone is new to the team, they can quickly understand the project’s objectives and the conventions workers are following to get there. Even a veteran developer with the company will benefit from having a reference point to refresh their memory occasionally.
SRS vs. SDD Documents
System requirements specifications (SRSs) and SDDs are easily confused because they’re so interconnected. While they both describe the team's approach to development, they do so from different vantage points:
- The SRS is granular. It uses diagrams and tables to document technical specifications, such as system architectures and database schemas.
- The SDD is a high-level overview. It details an overarching design philosophy the team should follow and provides examples they can use to guide their thinking. It’s a top-down description that outlines the project’s goals.
What Should a Software Design Document Include?
To create a useful software design document, include the following information:
- Stakeholders: List everyone involved in the project along with their roles and responsibilities. This will help team members decide who to contact when they need to escalate an issue or compare notes.
- Overview: Provide a high-level summary of the project that clarifies what you’re trying to build, why it matters and who it’s for.
- Context: Add useful background information describing how the software will fit into the market. And offer user stories that improve the team’s understanding of the product’s purpose and audience.
- UI mockups: Include wireframes and examples illustrating the project’s design philosophy.
- Components: Provide a list of the elements the team will need to create, such as buttons, icons and UI features.
- Conventions: Mention any style or structure guidelines so the finished product has a consistent design.
- Glossary: Give definitions for any technical terms you use in your design document so everyone understands their meaning.
How To Write Effective Software Design Documents: 7 Tips
Writing a quality SDD is a crucial first step in a smooth, efficient design process. Here are seven best practices for creating documentation that’ll streamline your project from beginning to end.
1. Define Scope and Objectives
Outline the project’s scope and goals so the team understands their responsibilities. Include clear deadlines and deliverables, and detail any limitations the team needs to stay within to maintain the project’s budget and timeline.
2. Use Wireframes
Provide mockups illustrating the finished software’s intended appearance and user experience (UX). If you have templates or examples from competitors, include those too, but clearly label them so designers know what’s intended for use and what’s purely for inspiration. These visual elements teach the team what they’re aiming to create and how all their components fit together.
3. Keep Language Simple
Avoid jargon and complex phases that could add confusion to your documentation — opt for plain language instead. Not all readers will have the same level of technical knowledge, so writing clearly ensures all stakeholders can understand the project vision.
4. Include User Stories
User stories add valuable context to the project by offering an outside perspective on what the team is doing. They remind UX designers, developers and engineers who they’re doing this work for and how it can help.
5. Offer Resources
Include a section that links to style guides, architectural diagrams and recommended specs. UX designers and developers might need to reference these documents to answer common questions.
6. Identify a Repository
Explain where the team should put all the finished UI elements, UX flows and components so everything’s in the same place. For example, Figma is a good option for storing design elements, since it has strong prototyping and collaboration capabilities.
7. Get Feedback
Ask stakeholders to provide feedback on the SDD to ensure it adequately meets the needs of everyone on the development team. Use documentation software, like Scribe, so collaborators can leave detailed comments or react with quick emojis to share their thoughts in real time.
Create Crystal-Clear Documentation With Scribe
The more straightforward your design specifications are, the better off every stakeholder will be. As questions and challenges arise, they’ll have a reliable resource to reference, reducing common friction points in software engineering and design.
If you’re ready to write your own documentation, consider using Scribe. With our platform, you can generate process instructions, create templates and develop guides in minutes. Try the AI Documentation Generator to build your next design document, or pick a template from the Scribe Gallery to give yourself a head start on IT documentation.