Test Design Techniques (During Designing Test Cases) (for Black Box Testing):

        • Equivalence Class Partitioning (ECP)
        • Boundary Value Analysis (BVA)
        • Decision Table
        • State Transition
        • Error Guessing

1.Equivalence Class Partitioning (ECP):

  • Partition data into various classes and we can select data according to class then test. It reduces the number of tests cases and saves time for testing.
  • Value Check.
  • Classify/divide/partition the data into multiple classes.

Example 1:

Example 2: 



2.Boundary Value Analysis (BVA):

  • Mainly we focus on boundaries of the value.
  • Here we consider 6 factors: Min, Min + 1, Min - 1, Max, Max + 1, Max – 1.

3.Decision Table:

  • Decision Table is also called a Cause-Effect Table.
  • This technique will be used if we have more conditions and corresponding actions.
  • In the Decision table technique, we deal with combinations of inputs.
  • To identify the test cases with a decision table, we consider conditions and actions.
  • If we have a greater number of conditions/actions, then we use the decision table technique.


Example for Decision Table:

  • Take an example of transferring money online to an account that is already added and approved.
  • Here the conditions to transfer money are,

    1. Account already approved.
    2. OTP (one-time-password) matched.
    3. Sufficient money in the account.

  • And the actions performed are,

    1. Transfer money.
    2. Show a message as the insufficient amount.
    3. Block the transaction in case of a suspicious transaction.

4.State Transition:

  • In State Transition Technique input is given in sequence one step at a time. Under this technique we can test for limited set of input values.
  • The technique should be used when the testing team wants to test sequence of events which happen in the application under test.
  • The tester can perform this action by entering various input conditions in a sequence.
  • In the State transition technique, the testing team provides positive as well as negative input test values for evaluating the system behavior.

5. Error Guessing:

  • Error guessing is one of the testing techniques used to find bugs in a software application based on the tester's prior experience.
  • In Error guessing we do not follow any specific rules.
  • It depends on Tester’s Analytical skills and experience.
  • Some of the examples are,

    1. Submitting a form without entering values.
    2. Entering invalid values such as entering alphabets in the numeric field.