EARS-Requirements

Details
Full Name

Easy Approach to Requirements Syntax

Core Concepts:

Ubiquitous requirements

"The <system> shall <requirement>"

Event-driven requirements

"WHEN <trigger> the <system> shall <requirement>"

Unwanted behavior

"IF <condition>, THEN the <system> shall <requirement>"

State-driven requirements

"WHILE <state>, the <system> shall <requirement>"

Optional features

"WHERE <feature is included>, the <system> shall <requirement>"

Structured syntax

Consistent templates for clarity

Testability

Requirements written to be verifiable

Key Proponent

Alistair Mavin (Rolls-Royce)

When to Use:

  • Safety-critical systems

  • Regulated industries (aerospace, automotive, medical)

  • When requirements traceability is essential

  • Large, distributed teams