State Transition Testing

What is State Transition Testing?

State transition testing is a black box technique used for systems whose behaviour depends on their current state and historical inputs, verifying that the system moves correctly between different states.

Key Concepts

• States: Distinct conditions the system can be in (e.g., "Logged Out," "Logged In," "Locked").
• Transitions: The valid changes from one state to another, triggered by specific events.
• Events: Actions or inputs that cause a state transition (e.g., entering a correct/incorrect password).

Test Design Using State Diagrams

Testers use state diagrams or state tables to visualise all valid states and transitions, then derive test cases that cover valid transitions, invalid transitions, and sequences of transitions (e.g., testing an account lockout after multiple failed login attempts).