The need for architecture documentation often gets ignored, and teams start working on implementation without understanding the overall architecture. A SAD provides a broad view of the overall solution design to keep all stakeholders informed.

The SAD helps to achieve the following purposes:

• Communicate the end-to-end application solution to all stakeholders.
• Provide high-level architecture and different views of the application design to address the application's service-quality requirements such as reliability, security, performance, and scalability.
• Provide traceability of the solution back to business requirements and look at how the application is going to meet all functional and non-functional requirements (NFRs).
• Provide all views of the solution required for design, build, testing, and implementation.
• Define the impacts of the solution for estimation, planning, and delivery purposes.
• Define the business process, continuation, and operations needed for a solution to work uninterrupted after the production launch.

SADs not only define the purpose and goal of the solution but also address critical components such as solution constraints, assumptions, and risks that often get overlooked by the implementation team. The solution architect needs to make sure they create the document in an easy language that business users can understand and relate business context with technical design. Documentation helps to retain knowledge due to resource attrition and makes the overall design process a people-independent one.

For existing applications where modernization effort is needed, a SAD presents an abstract view of current and future architecture, along with a transition plan. The solution architect understands the existing system dependencies and documents them to uncover any potential risk in advance. The migration plan helps businesses to understand the tools and technology required to handle the new system and plan resources accordingly.

During solution design, the solution architect conducts various assessments by building a proof of concept (POC) or through market research. A SAD should list all architecture assessments and their impact, along with the choice of technology. A SAD presents a conceptual view of the current and target state of the solution design and maintains a record of change. Let's understand various aspects of a SAD, in the next section.