LEARN. PRACTICE. GROW.Concept and mechanism
Equivalence partitioning groups values expected to receive similar treatment. An integer field from 10 through 200 inclusive has, in this example, below-range, within-range, and above-range partitions. Values 9, 100, and 201 cover those three partitions. For two-value BVA at both boundaries, use 9, 10, 200, and 201. Decision tables organize condition combinations and actions; states help select sequences and prohibited attempts. Always define the data domain and rules before calculating coverage so that the denominator is meaningful.
Guided application
For a transfer, model active account and sufficient funds as two Boolean conditions: the full table has four combinations if all are feasible. For cancellation, identify states where the action is allowed and test rejection in other states. Statement and branch coverage measure different elements: executing every statement does not guarantee exercising the false branch of an IF without ELSE. Complement techniques with charter-guided exploration, failure experience, and acceptance examples discussed with business. An expected result should come from a valid reference, not merely the code’s current output.
An EXECUTED request cannot be canceled. Prepare that state, attempt cancellation, and verify rejection without improper reversal of the financial effect.
Common pitfalls
Using only internal values; counting conditions as combinations; assuming 100% statements means 100% branches; exploring without retaining evidence.
Related topics: Risk, defects, and release decisions · Tools and confidence in the signal
Choose the technique according to the rule, define coverage, and verify observable effects.
Reference: ISTQB CTFL syllabus v4.0.1 · CTFL v4.0; syllabus v4.0.1 (2024-09-15)