Stress Testing
Stress testing is a type of performance testing that evaluates how a system behaves under workloads beyond its expected operational limits.
“A type of performance testing conducted to evaluate a system or component at or beyond the limits of its anticipated or specified workloads, or with reduced availability of resources such as access to memory or servers.”
(Definition reproduced from the ISTQB Glossary. Copyright belongs to ISTQB.)
View the complete ISTQB GlossaryWhat is Stress Testing?
The objective is to identify breaking points, evaluate stability, and verify that the system recovers appropriately after overload conditions.
Extreme workload: Tests beyond normal operating capacity.
Failure analysis: Identifies system limits and bottlenecks.
Recovery verification: Evaluates behavior after overload.
Real World Example
A national travel service is preparing for a public holiday sale where thousands of users may search, reserve, and pay for tickets at the same time.
A feature that works for one tester may fail under traffic, resource pressure, or infrastructure disruption. Stress testing helps the team focus on behavior under operational conditions.
The tester defines realistic traffic, failure, and recovery situations, then watches response time, errors, data consistency, and whether users can continue critical actions.
The release decision improves because Stress testing gives stakeholders evidence about service behavior when demand or disruption is no longer theoretical.
Practice Questions
Question 1
Which statement BEST describes Stress testing in the context of ISTQB terminology?
Question 2
A tester needs to explain Stress testing to a non‑technical stakeholder. Which approach is MOST appropriate?
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