Specification

A specification is a precise statement describing requirements for a product, service, system, or component, including design constraints, performance targets, and acceptance criteria. It functions as a contract among stakeholders and a reference for development, testing, and procurement.

Specifications vary by domain. Functional specifications describe intended behavior, features, and interactions; technical or engineering specifications define materials, dimensions, interfaces, tolerances, and standards; performance specifications state measurable targets such as speed, accuracy, or capacity; interface specifications define how components connect.

Quality characteristics of a good spec include clarity, completeness, consistency, verifiability, feasibility, and traceability. They are versioned and controlled to enable change management and to support verification and validation activities.

The spec is typically produced during requirements analysis and design phases. It serves as a basis for implementation, testing, procurement, and regulatory compliance, and it is used to verify that delivered outputs meet agreed criteria.

Examples include a software specification outlining functional requirements and API contracts; a hardware specification detailing electrical interfaces and tolerances; a product specification specifying materials, dimensions, and safety standards.