Black Box Testing Techniques: Boundary Value Analysis

 In previous articles we learned about Testing Techniques Overview and then Specification Based Testing Techniques or Black Box testing techniques overview.

Specification Based Testing Techniques(click here to read)

• Equivalence Partitioning 
• Boundary Value Analysis
• Decision Table Testing
• State Transition Testing 
• Use Case Testing
• Cause-effect graph
• Classification tree method
• Domain Analysis

  In this article we will learn about Test Designing Technique

Boundary Value Analysis

A black box test design technique in which test cases are designed based on boundary values. [ISTQB glossary]

• This technique is often considered as an extension of equivalence partitioning. 
• Behavior at the edge of each equivalence partition is more likely to be incorrect, so boundaries are an area where testing is likely to yield defects. 
• The minimum and maximum values of a partition are its boundary values. 
• Focuses on testing data values on and around the boundaries of an equivalence partition. Test cases cover both valid and invalid values.
• Can be used as two boundary analysis or three boundary analysis depends on project risk
• In BVA Rather than selecting any element in an equivalence class as being representative, elements are selected such that each edge of the EC is the subject of a test 

 When to use BVA: 

• It is suitable for systems in which inputs take values within ranges. 
• Data sets have no boundaries and thus BVA is not applicable for them. Same as EP, BVA can be applied at any level of testing.

 Examples