Systems analysis and design, an interdisciplinary part of science, may refer to:

• Systems analysis, a method of studying a system by examining its component parts and their interactions
  • Structured data analysis (systems analysis), analysing the flow of information within an organization with data-flow diagrams
• Systems design, the process of defining the architecture, components, and data of a system to satisfy specified requirements
• Object-oriented analysis and design, an approach to analysis and design of an application, system, or business that emphasizes modularity and visual modeling
• Service-oriented analysis and design, a method of service-oriented modeling to design business systems
• Structured analysis, methods in software engineering for converting specified requirements into software programs and hardware configurations
• Structured systems analysis and design method, a systems approach to the analysis and design of information systems

• Structured data analysis (disambiguation)
• Systems thinking, examining complex systems as a whole