The System Architecture Document (SAD) is an essential deliverable in the Software Development Life Cycle (SDLC), defining the structure, interactions, and dependencies of system components. It serves as a blueprint for the technical team to design and implement the software system in alignment with business and technical goals. This document is pivotal for ensuring scalability, maintainability, and alignment with system requirements.
Purpose of the System Architecture Document
1. Define System Blueprint: Provides a holistic overview of how system components interact.
2. Ensure Consistency: Aligns development with architectural principles and design patterns.
3. Facilitate Collaboration: Offers a shared understanding among stakeholders, including developers, architects, and project managers.
4. Mitigate Risks: Identifies potential design bottlenecks and scalability challenges early.
5. Support Maintenance: Serves as a reference for future system enhancements or debugging.
Structure of a System Architecture Document
A typical SAD is structured to include comprehensive technical details while maintaining clarity for diverse stakeholders.
1. Introduction:
Objective: State the purpose and scope of the architecture.
References: Link to related documents (e.g., FRD, TRD).
2. System Overview:
Description: High-level description of the system’s purpose and functionality.
Goals: Architectural objectives like performance, reliability, and security.
3. Architecture Design:
Logical Architecture:
Description of system modules and their responsibilities.
High-level component diagrams.
Physical Architecture:
Deployment architecture (e.g., cloud/on-premise).
Network topology diagrams.
4. Technology Stack:
Programming languages, frameworks, and libraries.
Database systems and storage solutions.
Third-party integrations and APIs.
5. Data Flow:
Sequence diagrams or data flow diagrams illustrating key processes.
6. Component Interaction:
Communication protocols (e.g., REST, gRPC).
Event-driven mechanisms or service orchestration.
7. Non-Functional Requirements (NFRs):
Performance benchmarks (e.g., latency, throughput).
Scalability and fault-tolerance strategies.
Security requirements (e.g., encryption standards).
8. Deployment Architecture:
Infrastructure design (e.g., containers, virtual machines).
CI/CD pipelines and release processes.
9. Risk Assessment:
Architectural risks and mitigation strategies.
10. Appendices:
Glossary of technical terms.
Links to diagrams or external documentation.
System Architecture Document
1. Introduction
Objective: Develop an e-commerce platform capable of handling 10,000 concurrent users.
References: FRD for functional specifications, NFR document for scalability requirements.
2. System Overview
Description: A multi-tiered web application for online shopping.
Goals: Ensure high availability and minimal latency (< 200ms).
3. Architecture Design
Logical Architecture:
Frontend: React-based SPA.
Backend: Node.js with Express.
Database: PostgreSQL for relational data and Redis for caching.
Physical Architecture:
Hosted on AWS, using EC2 and RDS instances.
4. Technology Stack
Languages: JavaScript, TypeScript.
Frameworks: React, Node.js.
Storage: PostgreSQL, Redis.
5. Data Flow
Checkout Process:
1. User adds items to the cart (frontend).
2. Cart data is sent to the backend for validation.
3. Payment is processed via a third-party API.
4. Order confirmation is saved in PostgreSQL.
6. Non-Functional Requirements
Performance: 99.9% uptime.
Security: Enforce HTTPS and OAuth2 for user authentication.
7. Deployment Architecture
Infrastructure: Docker containers orchestrated by Kubernetes.
CI/CD Pipeline: Jenkins for automated testing and deployment.
8. Risk Assessment
Risk: High traffic causing server crashes.
Mitigation: Implement load balancing and auto-scaling.
Importance of SAD in SDLC
Decision Support: Helps in making informed design and technology decisions.
Transparency: Provides clarity for stakeholders at all levels.
Standardization: Ensures development adheres to predefined architectural principles.
Adaptability: Simplifies scaling or modifying the system as requirements evolve.
The System Architecture Document (SAD) is indispensable for large-scale software projects, ensuring the system design is both robust and aligned with business objectives. Its comprehensive structure and technical focus ensure that the resulting system meets current needs and anticipates future challenges.
The article above is rendered by integrating outputs of 1 HUMAN AGENT & 3 AI AGENTS, an amalgamation of HGI and AI to serve technology education globally.