Open-loop-system
An open-loop system is a system that performs actions without using feedback to adjust or correct its behavior during operation.
“A system in which controlling action or input is independent of the output or changes in output.”
(Definition reproduced from the ISTQB Glossary. Copyright belongs to ISTQB.)
View the complete ISTQB GlossaryWhat is Open-loop-system?
Unlike a closed-loop system, an open-loop system does not monitor its output to determine whether the intended result has been achieved.
No feedback: Output does not influence future actions.
Simple operation: Behavior follows predefined instructions.
Testing focus: Verify expected behavior under defined input conditions.
Real World Example
A regulated product team is preparing a release where Open-loop-system appears in reviews, test design conversations, or defect triage rather than as an isolated glossary word.
The risk is that the team treats Open-loop-system as interchangeable with nearby ISTQB terms. That makes test scope blurry and can lead to weak evidence for the release decision.
The tester anchors the discussion in the official definition, asks where the concept appears in the product, and designs examples that show the difference between Open-loop-system and similar ideas.
The page becomes useful in practice because Open-loop-system is connected to a specific testing decision, not memorized as a detached definition.
Practice Questions
Question 1
Which statement BEST describes Open-loop-system in the context of ISTQB terminology?
Question 2
A tester needs to explain Open-loop-system to a non‑technical stakeholder. Which approach is MOST appropriate?
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