TESTING - Testing Techiniques (Cont.)

White Box Testing:

- Verifies that the software design is valid and also whether it was built according to the specified design.

- Statement coverage – execute all statements atleast once.

- Decision coverage – execute each decision direction atleast once.

- Condition coverage – execute each decision with all possible outcomes atleast once.

- Decision/condition coverage – execute all possible combinations of condition outcomes in each decision. Treat all iterations as two way conditions exercising loops zero times and once.

- Multiple condition coverage – invokes each point of entry atleast once.

Black Box Testing:

- Tests customer software requirements.

- Focus on the functional requirements of the software.

- Attempts to find incorrect or missing functions, errors in data structures or external database access, interface errors, performance errors and initialization and termination errors.

- Conducted on integrated, functional components whose design integrity has been verified thro’ completion of traceable white box tests.

- Three techniques.

· Equivalence Partitioning – an equivalence class is a subset of data that is representative of a larger class.

Eg: A program for credit limits between $10,000 - $15,000

Less than 10,000 - Invalid

$10,000 - $15,000 - Valid

More than $15000 - Invalid

· Boundary Analysis – a technique that consists of a developing test cases and data that focus on the input and output boundaries of a given function.

Eg: Same credit limit.

Low boundary plus or minus one ($9,999 and $10,001)

On the boundary ($10,000 - $15,000)

Upper boundary plus or minus one ($14,999 and $15,000)

· Error Guessing – based on the theory that cases can be developed upon the intuition and experience of the test engineer.