System Design Document (SDD) Template
Follows industry-standard practices inspired by IEEE 1016.
Design Viewpoints Summary
Table 1 — Summary of Design Viewpoints (IEEE 1016)
| Design Viewpoint | Design Concerns | Example Design Languages |
|---|---|---|
| Context (5.2) | Systems services and users | IDEF0, UML use case diagram, Structured Analysis context diagram |
| Composition (5.3) | Composition and modular assembly of systems in terms of subsystems and pluggable | |
| components, buy vs. build, reuse | Logical: UML package/component diagram, IDEF0, Structure chart, HIPO. Physical: | |
| UML deployment diagram | ||
| Logical (5.4) | Static structure (classes, interfaces, relationships). Reuse of types and implementations | |
| UML class diagram, UML object diagram | ||
| Dependency (5.5) | Interconnection, sharing, and parameterization | UML package and component diagram |
| Information (5.6) | Persistent information (with data distribution and physical volumetric overlays) | IDEF1X, |
| ER diagram, UML class diagram | ||
| Patterns (5.7) | Reuse of patterns and available framework templates | UML composite structure diagram |
| Interface (5.8) | Service definition, service access | IDL, UML component diagram |
| Structure (5.9) | Internal constituents and organization of design subjects | UML structure diagram, class |
| diagram | ||
| Interaction (5.10) | Object communication, messaging | UML sequence diagram, communication diagram |
| State Dynamics (5.11) | Dynamic state transformation | UML state machine, statechart, state transition table, |
| Petri net | ||
| Algorithm (5.12) | Procedural logic | Decision table, Warnier diagram, JSP, PDL |
| Resources (5.13) | Resource utilization | UML Real-time Profile, UML OCL |
1. Document Control
| Field | Value |
|---|---|
| Document Version | |
| Date | |
| Author(s) | |
| Reviewed by | |
| Approved by | |
| Status | Draft / Final |
2. Introduction
2.1 Purpose
Explain the purpose of this document, its intended audience, and scope.
2.2 Scope
Describe the system's overall goals, business context, and key functionalities.
2.3 References
List all referenced documents, standards, or related designs.
2.4 Definitions & Acronyms
Provide a glossary of terms and abbreviations.
3. System Overview
3.1 System Context
- High-level description of the system
- Include System Context Diagram (showing external systems and actors)
3.2 Objectives & Success Criteria
Define measurable goals for the system.
4. Architectural Design
4.1 Architecture Overview
- Describe chosen architectural style (e.g., microservices, layered, event-driven)
- Show high-level architecture diagram
4.2 Design Principles
List guiding principles (e.g., scalability, availability, security).
4.3 Subsystems & Components
Break down into major components/modules:
- Name
- Responsibility
- Interfaces
- Dependencies
4.4 Data Design
- Database schema diagrams
- Data flow diagrams
- Key data entities & relationships
4.5 Technology Stack
Specify technologies chosen (languages, frameworks, infra, databases, messaging, etc.)
5. Detailed Design
For each component/subsystem:
- Name
- Purpose
- Inputs / Outputs
- Interfaces (APIs, protocols, message formats)
- Internal Processing
- Data Storage
- Dependencies
- Error Handling & Logging
Use UML diagrams where helpful: class diagrams, sequence diagrams, state diagrams.
6. Integration & Interfaces
6.1 External Interfaces
APIs, services, third-party integrations.
6.2 Internal Interfaces
Communication between modules.
6.3 Data Migration / Legacy System Considerations
7. Security Design
- Authentication & Authorization
- Data protection (encryption, secure storage)
- Network security (firewalls, TLS, etc.)
- Compliance considerations (GDPR, HIPAA, PCI DSS, etc.)
8. Performance & Scalability
- Expected loads and throughput
- Latency requirements
- Scalability strategies (sharding, caching, load balancing)
9. Reliability & Availability
- Fault tolerance strategies
- Backup & disaster recovery plan
- High availability design
10. Deployment & Infrastructure
- Environment setup (Dev, Staging, Prod)
- Infrastructure design (cloud/on-prem, containers, orchestration)
- CI/CD pipeline overview
- Monitoring & logging strategy
11. Non-Functional Requirements
- Security
- Performance
- Usability
- Maintainability
- Extensibility
- Compliance
12. Risks & Mitigations
- Technical risks
- Business risks
- Mitigation strategies
13. Appendix
Supporting diagrams, extra notes, calculations, POCs.