System testing uses black box testing techniques. There are 4 techniques in Black box

  1. Boundary Value Analysis (BVA)
  2. Equivalence Class Partitions (ECP)
  3. Decision Tables (DT)
  4. State Transition Diagrams (STD)

Boundary Value Analysis (BVA): BVA takes care about the size in software testing

For example: Testing Password Field, Password field should be minimum 4 chars and maximum 8 chars. BVA for this is

  • Min=4
  • Min-1=3
  • Min+1=5
  • Max=8
  • Max-1=7
  • Max+1=9

Equivalence Class Partitions (ECP): ECP takes care about the Type in software testing.

For example: Testing username Field, User name should be combination of Capital letters and numbers.

Note: If our Test is related to a field, the testers are using BVA and ECP techniques because exhaustive testing is impossible from testing principles

Decision Tables: If our test related to an operation with alternative expectations, the testers are using DT techniques.

For example: If login user name and password are correct, next window will appear. If any one of user name or password is are wrong, error window should open. So here we have 2 alternatives like Next window and error window.

State Transition Diagrams (STD): If a test related to an operation with no alternative expectations, the testers are using state transition diagrams.