CTFL_Syll_4.0 Exam Dumps : ISTQB Certified Tester Foundation Level (CTFL) v4.0

Theratio-based estimation methodrelies on historical relationships betweendevelopment and testing effort.

Using the given5:3 ratio:

Thus, the correct answer is270 person-days (D).

(A) and (C) are incorrectas they overestimate the effort.

(B) underestimates the testing effort based on the ratio.

Ratio-based estimationhelps allocate resources effectively based on past project data.

Product risksare risks thatimpact the quality or functionality of the software, whereasproject risksaffect theprocess, resources, or timeline.

(A) is correctbecause incorrect calculations impact software correctness.

(B), (C), and (D) are project risksas they relate toteam coordination, staffing, and schedulingrather than software defects.

Identifyingproduct risksearlyimproves defect detection and ensures better coverage for high-risk areas.

Comprehensive and Detailed Explanation From Exact Extract:

This question applies theState Transition Testingtechnique.

Let’s evaluateOption Dstep-by-step:

NORMAL MODE → DEGRADED MODE:✅Valid on“FAILURE DETECTED”

DEGRADED MODE → NORMAL MODE:✅Valid on“ALL FAILURES CLEARED”

NORMAL MODE → DIAGNOSTIC MODE:✅Valid on“SELF DIAGNOSTIC INITIATED”

DIAGNOSTIC MODE → DEGRADED MODE:❌Invalid– there isno defined transitionfrom DIAGNOSTIC MODE directly to DEGRADED MODE.

According to the state diagram, DEGRADED MODE can only be entered:

From NORMAL MODE (on FAILURE DETECTED), or

Not from DIAGNOSTIC MODE at all.

This violates the rule:

“State transition testing uses a model where test cases are designed to execute valid and invalid transitions.”

(ISTQB CTFL Syllabus v4.0, Section 4.2.4 – State Transition Testing, Page 40)

Thus, OptionDcontains aninvalid transition, making it the correct answer.