Use the online glossary hereafter to read error, defect, and failure definitions.
ISTQB Glossary: https://glossary.istqb.org/en/search/
An example for the learning objective: “Distinguish between error, defect, and failure”
Let’s consider the case of a health insurance software that calculates the waiting period for insurance clients. Regarding your policy, the waiting period is the amount of time you need to wait for, from its start, to use its benefits.
Unfortunately, the software requirements initially contained an incorrect rule for calculating the waiting period. It was due to a lack of knowledge. Once in production, we saw a failure after a few days: some clients did not agree with their waiting period as calculated by the insurance software.
The lack of knowledge has led to a “defect” in the requirements. Then the programming “error” also led to another “defect” in the source code.
Now, can you distinguish between error, defect, and failure?
Use the exam question below as a self-assessment. (Question #3 from the ISTQB CTFL 2018 Sample Exam B v1.3 Questions)
Which of the following is an example of a failure in a car cruise control system?
a) The developer of the system forgot to rename variables after a cut-and-paste operation
b) Unnecessary code that sounds an alarm when reversing was included in the system
c) The system stops maintaining a set speed when the radio volume is increased or decreased
d) The design specification for the system wrongly states speeds
Select ONE option.