About black Box testing

Black box testing focuses on the external structure of the program, regardless of the internal logic structure, mainly for the software interface and software function testing, the user's point of view, from the input data and output data corresponding relationship from the test.

The main classifications are equivalence class partitioning, causality diagram, decision table, boundary value test, and orthogonal experimental design.

The equivalence class partitioning method was specifically written in previous blogs and is not mentioned here.

　　　

Causality diagram method: Use steps:

1) Analyze what is the reason and what is the result of the description of the software specification. The reason is the equivalence class of the input or input condition, and the result is the output condition.　　Give each reason and result and give an identifier, according to these relationships, draw a causal diagram.　　2) The cause and effect diagram uses some marks to indicate the restriction condition or the restriction condition.　　3) Analyze the requirements and represent them as diagrams between causal plots.　　4) Convert the causality diagram into a decision table. 5) Use each column of the decision table as the basis for designing the test case.

Decision Table method: The various combinations of all inputs as a condition and the corresponding output values are listed to form the box

For the decision table with n conditions, the corresponding state has 2^n, when n is large, some items in the General Judgment table can be simplified.

Boundary value test: to design test cases for various boundary conditions, more errors can be detected. Using the Boundary value analysis method to design test cases, the boundary condition should be determined first. The boundary of the equivalence class and the output equivalence class is usually entered, which is the boundary condition that should be tested emphatically. Values that are exactly equal to, just above, or just below the boundary should be selected as test data instead of the typical value in the equivalent class or any value as test data.

Orthogonal experiment Design method: Step:

1) determine the test factors and level number;　　　　2) Select the appropriate orthogonal table;　　　　3) List the test plan and test results;　　　　4) The orthogonal test design results are analyzed, including the extreme difference analysis and variance analysis; 5) determine the optimal or superior factor level combination.

About black Box testing