CTAL-TTA Exam Dumps : Certified Tester Advanced Level Technical Test Analyst

Analysis:

For a system to meet its reliability requirements, it must maintain a mean time between failure (MTBF) of three months or longer and a mean time to repair (MTTR) of ten minutes or less. When planning and specifying reliability tests, several factors must be considered to ensure these requirements are met.

Key Factor:

B. Determining the target availability for the system:

Availability is a critical factor that encompasses both the MTBF and MTTR. Availability is calculated based on the uptime and downtime of the system, which directly correlates with MTBF and MTTR. Determining the target availability helps ensure that the system can meet the required reliability standards by specifying acceptable levels of uptime and downtime.

Explanation of Incorrect Options:

A. Defining the replaceability requirements:

Replaceability pertains to the ease with which components can be replaced or updated. While important for maintainability, it is not the primary focus for reliability testing in this context.

C. Monitoring reliability in production:

Monitoring in production is important for ongoing reliability assessment but is not a primary consideration when planning and specifying tests before release.

D. Configuring a production-like test environment:

This is essential for accurate testing but is a logistical consideration rather than a direct factor in the reliability requirements.

References:

The ISTQB CTAL-TTA syllabus and standard practices in reliability testing emphasize the importance of availability metrics in planning reliability tests.

Sources:

ISTQB-CTAL-TTA Syllabus

General knowledge on reliability testing and availability.

Program tax check

Integer: tax_rate

real: tax%

BEGIN

tax% := 0

GET (tax_rate)

WHILE tax_rate > 0 loop

IF tax_rate > 3 THEN

tax_rate := 3

ENDIF

tax% := tax% + (tax_rate / 10)

tax_rate := tax_rate - 1

ENDLOOP

IF tax% > 0.6 THEN

print ("tax rate is high")

ELSEIF tax% < 0.1 THEN

print ("tax rate is zero")

ELSE

print ("tax rate is low")

ENDIF

END tax check

Explanation of Control Flow:

Initialization:

tax% := 0

Get Tax Rate:

GET (tax_rate)

While Loop:

Loop runs while tax_rate > 0.

Inside the loop:

If tax_rate > 3, set tax_rate to 3.

Update tax% by adding tax_rate / 10.

Decrement tax_rate by 1.

Post-Loop Condition Checks:

After the loop, check the value of tax%:

If tax% > 0.6, print "tax rate is high".

Else if tax% < 0.1, print "tax rate is zero".

Otherwise, print "tax rate is low".

Unreachable Code Analysis:

The ELSEIF tax% < 0.1 THEN condition (line 17) is unreachable.

In the loop, tax% is incremented by a minimum of 0.1 each time tax_rate is greater than 0.

Therefore, tax% cannot be less than 0.1 after the loop.

Conclusion:

Line 17 (ELSEIF tax% < 0.1 THEN) will never be true given the logic of the loop.

To determine the percentage of decision testing coverage achieved by the given suite of test cases, we need to analyze the decisions and outcomes in the provided logic.

Detailed Analysis

Identify all decisions in the logic:

IF account number is valid

IF customer account is active

IF oldBalance < zero

IF balance now >= zero

IF account holder is VIP customer

Calculate the number of unique decisions:

There are 5 unique decision points in the logic.

Determine the possible outcomes for each decision:

IF account number is valid → 2 outcomes (True, False)

IF customer account is active → 2 outcomes (True, False)

IF oldBalance < zero → 2 outcomes (True, False)

IF balance now >= zero → 2 outcomes (True, False)

IF account holder is VIP customer → 2 outcomes (True, False)

Test Cases Analysis

Test Case A

Account number valid → True

Account is active → True

OldBalance = -100 → True (less than zero)

Balance now = +200 → True (greater than zero)

Not a VIP customer → False

Test Case B

Account number valid → True

Account is active → True

OldBalance = -100 → True (less than zero)

Balance now = -50 → False (less than zero)

Is a VIP customer → True

Coverage Calculation

To calculate the decision coverage, we need to see how many of the possible outcomes are covered by the test cases:

IF account number is valid (True in both A and B, False not tested)

IF customer account is active (True in both A and B, False not tested)

IF oldBalance < zero (True in both A and B, False not tested)

IF balance now >= zero (True in A, False in B, both outcomes tested)

IF account holder is VIP customer (False in A, True in B, both outcomes tested)

Out of the 10 possible outcomes (2 for each decision), the given test cases cover 6 outcomes:

Account number valid → True

Account number valid → False (not covered)

Customer account active → True

Customer account active → False (not covered)

OldBalance < zero → True

OldBalance < zero → False (not covered)

Balance now >= zero → True

Balance now >= zero → False

Account holder is VIP → True

Account holder is VIP → False

Thus, 6 out of the 10 outcomes are covered by the test cases, giving us a decision coverage percentage of:

Decision Coverage=(610)×100%=60%\text{Decision Coverage} = \left(\frac{6}{10}\right) \times 100\% = 60\%Decision Coverage=(106​)×100%=60%

References:

The sample questions and answers provided in the ISTQB CTAL-TTA documentation confirm this calculation method and the expected coverage percentage for similar logical scenarios​​​​​​.