Testing Techniques

1.Equivalence partitioning
Equivalence partitioning is a Software testing related technique with the goal:

• To reduce the number of test cases to a necessary minimum.
• To select the right test cases to cover all possible scenarios.

The equivalence partitions are usually derived from the specification of the component's behavior.An input has certain ranges which are valid and other ranges which are invalid.

Example: To check the month of a date. The valid range for the month is 1 to 12. This valid range is called a partition. Example for invalid range are <= 0 and >= 13.

2.Boundary value analysis(BVA)
To set up boundary value analysis test cases,determine the boundaries at the interface of a software component.This has to be done by applying the equivalence partitioning technique. Boundary value analysis and equivalence partitioning are inevitably linked together.
The boundary value analysis can have 6 test cases. n, n-1,n+1 for the upper limit and n, n-1,n+1 for the lower limit.
Guidelines for BVA are close to those for equivalence partitioning:

• If an input condition specifies a range bounded by values a and b, test cases should be produced with values a and b, just above and just below a and b, respectively.
• If an input condition specifies various values, test cases should be produced to exercise the minimum and maximum numbers.
• If internal program data structures have prescribed boundaries, produce test cases to exercise that data structure at its boundary.

3.Cause-Effect Graphing Techniques
Cause-effect graphing is a test case design approach that offers a concise depiction of logical conditions and associated actions. The approach has four stages:

• Cause (input conditions) and effects (actions) are listed for a module and an identifier is allocated to each.
• A cause-effect graph is created.
• The graph is altered into a decision table.
• Decision table rules are modified to test cases.