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ISEB-SWTINT1 · Question #45

Scenario 1 A computerised system is being created to monitor the life support system on board a submarine. It monitors air quality, water supplies and temperature. This system will be supplied and…

The correct answer is C. That the system has been tested at levels of oxygen usage well beyond anticipated personnel. Option C is correct because site acceptance testing (SAT) is the final V-model test level, conducted in the real operational environment - its entry criteria must confirm that all prior testing phases are complete. Testing oxygen usage well beyond anticipated personnel loads…

Test Management

Question

Scenario 1 A computerised system is being created to monitor the life support system on board a submarine. It monitors air quality, water supplies and temperature. This system will be supplied and maintained by SubsInc. SubsInc uses the V-model for software development and conducts four levels of testing, from unit through to operational and site acceptance testing. Two key risks identified for the air quality system are: 1. If the percentage of oxygen in the air falls too low, personnel may suffocate 2. If the concentration of carbon dioxide in the air rises too high, the air may become toxic. To address these risks, the requirement specification for this system includes the following requirements: R1) Oxygen must be replaced as it is consumed. R2) Carbon dioxide must be removed from the air. These requirements must be reflected in the functional, technical and program specification documents. You are a newly recruited test manager. Which of the following would be an entry criterion into site acceptance testing for the air quality monitoring system?

Options

  • AThat the code written to fulfil the requirement to monitor carbon dioxide levels has been 100% path
  • BThat the functional specification accurately reflects requirements R1 and R2.
  • CThat the system has been tested at levels of oxygen usage well beyond anticipated personnel
  • DThat the requirements for temperature control have been signed-off.

How the community answered

(23 responses)
  • A
    4% (1)
  • B
    9% (2)
  • C
    83% (19)
  • D
    4% (1)

Explanation

Option C is correct because site acceptance testing (SAT) is the final V-model test level, conducted in the real operational environment - its entry criteria must confirm that all prior testing phases are complete. Testing oxygen usage well beyond anticipated personnel loads (stress/robustness testing) is a system-level activity that must be signed off before SAT can begin, ensuring the system is ready for live operational conditions aboard the submarine.

Why the distractors are wrong:

  • A is wrong because 100% path coverage is a unit testing metric - it belongs at the lowest level of the V-model, not as a precondition for the highest.
  • B is wrong because verifying the functional specification against requirements is a pre-development or early-phase review activity; it would be an entry criterion for lower test levels (e.g., integration testing), not SAT.
  • D is wrong because temperature control requirements sign-off is a different subsystem concern and belongs to the requirements/design phase, not a meaningful entry gate for the air quality system's SAT.

Memory tip: Map entry criteria to the V-model "level" - SAT criteria must prove that system-level testing is done and passed, not that documents are correct (too early) or code coverage is met (too low). If the criterion sounds like it belongs on the left side of the V, it's too early for SAT.

Topics

#risk-based testing#acceptance criteria#safety-critical testing#operational testing

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