learning target
Grasp the core of cause and effect diagram method to master the basic symbols understand cause and effect diagram drawing causal map
1. What is the cause and effect diagram method
FIG method is a cause and effect analysis of various combinations of inputs using graphical method to test design method, which is suitable for various combinations of input conditions of the inspection procedure
Core 2, cause and effect diagram method
Because, if
a so-called reason is entered, the result is the so-called output.
2, FIG cause "cause" - input condition
3, in FIG cause "fruit" - output
Case: If the user arrears or power down, calling and called parties are not allowed to 
3, in symbolic causal FIG method
generally FIG causal reasons represented by Ci, the result represented by Ei, each node represents a state, the value "0" or "1."
"0" indicates that a state does not occur, "1" indicates a certain condition occurs. 
The basic steps of the method of FIG causal
1, identifies the input and output
analysis of test content, identify inputs and outputs and identify them out, which should pay attention to the following points:
1) input involves only two kinds of values, can only be used as a logo out, if the entry is involved the plurality of values, each value needed as an input identifier out
2) to determine their identification may, but need separate input and output identifier
2, shown in FIG cause
the causal relationship between input and output of the analysis, the input and output constraints between, according to these relationships, causal shown in FIG.
3, FIG convert causal determination table
1. the respective input and output operation of the pile and the pile writing condition, and the condition of the fill composition inputs item
2 FIG input conditions cause the constraints on the input impossible combination of deletion mark made on action items
according to FIG causality cause the input and output operation indicated in the action items corresponding to the results of
4, generate test cases
generated corresponding to test.
Case 1, if one wants to modify the file, the first character input column must be A or B, the second column of the character must be a number, if the first column is given incorrect character information L, the second column if the character is not correct, give information M
using the cause and effect diagram to analyze the problem
The first step: identify inputs and outputs
Step two: draw cause and effect diagram
The third step: converting the causality graph into a determination table as follows:
The fourth step: write test cases
FIG scope cause Method
1, applied to a plurality of inputs, a plurality of output conditions
have a problem of causality constraint and 2 between the input and output