SDD

SDD is an acronym used in multiple fields, and its meaning depends on the context. The two most common interpretations are Software Design Document and System Design Document, though in some organizations other meanings may be used.

Software Design Document (SDD) refers to a technical specification that describes the detailed design of a software system. Its purpose is to bridge requirements and implementation, guiding developers and testers. Typical content includes an overview of the system, architectural views, module decomposition, data models, interface specifications, algorithms and control flow, error handling, and nonfunctional requirements such as performance, security, and reliability. It may also cover dependencies, constraints, risk assessments, and a traceability matrix linking requirements to design elements. The audience usually comprises software engineers, architects, and quality assurance teams, with the document serving as a reference throughout implementation and integration testing.

System Design Document (SDD) is used in systems engineering to capture the higher‑level design of a complete system. It outlines the system context, architecture, and how subsystems interact. Content typically includes a system overview, requirements traceability, subsystem decomposition, data and control flows, interface design (hardware, software, and human operators), security and reliability considerations, integration and deployment plans, and verification and validation strategies. It provides a blueprint for engineers across disciplines and supports coordination among stakeholders, suppliers, and deployment teams.

Other uses of the acronym exist in specific industries or organizations; always consult the relevant documentation to determine the intended meaning.