EARS Syntax

EARS Syntax

EARS Format

Easy Approach to Requirements Syntax for clear, unambiguous requirements.

Basic Pattern

While <precondition>, when <trigger>, the system shall <response>.

Pattern Types

Ubiquitous (Always True)

The system shall [action].

Example: The system shall encrypt all passwords using bcrypt.

Event-Driven

When [trigger], the system shall [action].

Example: When the user clicks "Submit", the system shall save the form data.

State-Driven

While [state], the system shall [action].

Example: While the user is logged in, the system shall display the dashboard.

Conditional (Most Common)

While [state], when [trigger], the system shall [action].

Example: While the cart contains items, when the user clicks "Checkout", the system shall navigate to the payment page.

Optional

Where [feature enabled], the system shall [action].

Example: Where two-factor authentication is enabled, the system shall require a verification code.

Examples by Domain

Authentication

**FR-AUTH-001**: Login
While credentials are valid, when POST /auth/login is called,
the system shall return JWT access token (15min) and refresh token (7d).

**FR-AUTH-002**: Invalid Login
When invalid credentials are provided,
the system shall return 401 and increment failed login counter.

**FR-AUTH-003**: Account Lockout
While failed login count exceeds 5, when login is attempted,
the system shall reject the attempt and require password reset.

E-commerce

**FR-CART-001**: Add to Cart
While user is logged in, when they click "Add to Cart",
the system shall add the item and update the cart badge count.

**FR-CART-002**: Apply Coupon
While the cart contains items, when a valid coupon code is applied,
the system shall reduce the total by the discount amount.

**FR-ORDER-001**: Checkout
While payment method is valid, when user confirms order,
the system shall create order, charge payment, and send confirmation email.

Data Management

**FR-EXPORT-001**: CSV Export
While user has data access permission, when they click "Export",
the system shall generate a CSV file and initiate download.

**FR-DELETE-001**: Soft Delete
When a resource is deleted,
the system shall set deleted_at timestamp instead of removing the record.

Quick Reference